Method and device for efficiently supporting nr v2x communication

ABSTRACT

A method for performing wireless communication by a first device is proposed. The method may comprise the steps of: transmitting first sidelink control information (SCI) related to initial transmission, to a second device through a first physical sidelink control channel (PSCCH), wherein the first SCI related to the initial transmission includes scheduling information of second SCI related to the initial transmission, which is transmitted through a first physical sidelink shared channel (PSSCH) related to the first PSCCH; transmitting, to the second device, a medium access control protocol data unit (MAC PDU) and the second SCI related to the initial transmission through the first PSSCH, wherein the second SCI related to the initial transmission includes location information of the first device, which is related to the initial transmission; transmitting first SCI related to retransmission, to the second device through a second PSCCH, wherein the first SCI related to the retransmission includes scheduling information of second SCI related to the retransmission, which is transmitted through a second PSSCH related to the second PSCCH; and transmitting, to the second device, the MAC PDU and the second SCI related to the retransmission through the second PSSCH, wherein the second SCI related to the retransmission includes the location information of the first device, which is related to the initial transmission.

TECHNICAL FIELD

This disclosure relates to a wireless communication system.

BACKGROUND

Sidelink (SL) communication is a communication scheme in which a directlink is established between User Equipments (UEs) and the UEs exchangevoice and data directly with each other without intervention of anevolved Node B (eNB). SL communication is under consideration as asolution to the overhead of an eNB caused by rapidly increasing datatraffic. Vehicle-to-everything (V2X) refers to a communicationtechnology through which a vehicle exchanges information with anothervehicle, a pedestrian, an object having an infrastructure (or infra)established therein, and so on. The V2X may be divided into 4 types,such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I),vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). The V2Xcommunication may be provided via a PC5 interface and/or Uu interface.

Meanwhile, as a wider range of communication devices require largercommunication capacities, the need for mobile broadband communicationthat is more enhanced than the existing Radio Access Technology (RAT) isrising. Accordingly, discussions are made on services and user equipment(UE) that are sensitive to reliability and latency. And, a nextgeneration radio access technology that is based on the enhanced mobilebroadband communication, massive Machine Type Communication (MTC),Ultra-Reliable and Low Latency Communication (URLLC), and so on, may bereferred to as a new radio access technology (RAT) or new radio (NR).Herein, the NR may also support vehicle-to-everything (V2X)communication.

FIG. 1 is a drawing for describing V2X communication based on NR,compared to V2X communication based on RAT used before NR. Theembodiment of FIG. 1 may be combined with various embodiments of thepresent disclosure.

Regarding V2X communication, a scheme of providing a safety service,based on a V2X message such as Basic Safety Message (BSM), CooperativeAwareness Message (CAM), and Decentralized Environmental NotificationMessage (DENM) is focused in the discussion on the RAT used before theNR. The V2X message may include position information, dynamicinformation, attribute information, or the like. For example, a UE maytransmit a periodic message type CAM and/or an event triggered messagetype DENM to another UE.

Thereafter, regarding V2X communication, various V2X scenarios areproposed in NR. For example, the various V2X scenarios may includevehicle platooning, advanced driving, extended sensors, remote driving,or the like.

SUMMARY

Meanwhile, in sidelink communication, when a transmitting UE initiallytransmits SL data to a receiving UE, the transmitting UE may transmitlocation information of the transmitting UE to the receiving UE.Thereafter, for example, when the transmitting UE retransmits SL data tothe receiving UE, if the location of the transmitting UE is changed, itmay be a problem which location information the transmitting UEtransmits to the receiving UE.

In an embodiment, proposed is a method for performing wirelesscommunication by a first device. The method may comprise: transmitting,to a second device, first sidelink control information (SCI) related toinitial transmission through a first physical sidelink control channel(PSCCH), wherein the first SCI related to the initial transmissionincludes scheduling information of second SCI related to the initialtransmission transmitted through a first physical sidelink sharedchannel (PSSCH) related to the first PSCCH; transmitting, to the seconddevice, the second SCI related to the initial transmission and a mediumaccess control (MAC) protocol data unit (PDU) through the first PSSCH,wherein the second SCI related to the initial transmission includeslocation information related to the initial transmission of the firstdevice; transmitting, to the second device, first SCI related toretransmission through a second PSCCH, wherein the first SCI related tothe retransmission includes scheduling information of second SCI relatedto the retransmission transmitted through a second PSSCH related to thesecond PSCCH; and transmitting, to the second device, the second SCIrelated to the retransmission and the MAC PDU through the second PSSCH,wherein the second SCI related to the retransmission includes thelocation information related to the initial transmission of the firstdevice.

In an embodiment, proposed is a first device adapted to perform wirelesscommunication. The first device may comprise: one or more memoriesstoring instructions; one or more transceivers; and one or moreprocessors connected to the one or more memories and the one or moretransceivers, wherein the one or more processors execute theinstructions to: transmit, to a second device, first sidelink controlinformation (SCI) related to initial transmission through a firstphysical sidelink control channel (PSCCH), wherein the first SCI relatedto the initial transmission includes scheduling information of secondSCI related to the initial transmission transmitted through a firstphysical sidelink shared channel (PSSCH) related to the first PSCCH;transmit, to the second device, the second SCI related to the initialtransmission and a medium access control (MAC) protocol data unit (PDU)through the first PSSCH, wherein the second SCI related to the initialtransmission includes location information related to the initialtransmission of the first device; transmit, to the second device, firstSCI related to retransmission through a second PSCCH, wherein the firstSCI related to the retransmission includes scheduling information ofsecond SCI related to the retransmission transmitted through a secondPSSCH related to the second PSCCH; and transmit, to the second device,the second SCI related to the retransmission and the MAC PDU through thesecond PSSCH, wherein the second SCI related to the retransmissionincludes the location information related to the initial transmission ofthe first device.

The user equipment (UE) can efficiently perform SL communication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing for describing V2X communication based on NR,compared to V2X communication based on RAT used before NR.

FIG. 2 shows a structure of an NR system, based on an embodiment of thepresent disclosure.

FIG. 3 shows a radio protocol architecture, based on an embodiment ofthe present disclosure.

FIG. 4 shows a structure of a radio frame of an NR, based on anembodiment of the present disclosure.

FIG. 5 shows a structure of a slot of an NR frame, based on anembodiment of the present disclosure.

FIG. 6 shows an example of a BWP, based on an embodiment of the presentdisclosure.

FIG. 7 shows a UE performing V2X or SL communication, based on anembodiment of the present disclosure.

FIG. 8 shows a procedure of performing V2X or SL communication by a UEbased on a transmission mode, based on an embodiment of the presentdisclosure.

FIG. 9 shows three cast types, based on an embodiment of the presentdisclosure.

FIG. 10 shows a method in which a UE that has reserved transmissionresource(s) informs another UE of the transmission resource(s), based onan embodiment of the present disclosure.

FIG. 11 shows a procedure for transmitting, by a transmitting UE, SCIincluding location information of the transmitting UE and a MAC PDU to areceiving UE, based on an embodiment of the present disclosure.

FIG. 12 shows another procedure for transmitting, by a transmitting UE,SCI including location information of the transmitting UE and a MAC PDUto a receiving UE, based on an embodiment of the present disclosure.

FIG. 13 shows an example in which the location of a transmitting UE ischanged, based on an embodiment of the present disclosure.

FIG. 14 shows a method for a first device to transmit SCI includinglocation information and a MAC PDU to a second device, based on anembodiment of the present disclosure.

FIG. 15 shows a method for a second device to receive SCI includinglocation information a MAC PDU from a first device, based on anembodiment of the present disclosure.

FIG. 16 shows a communication system 1, based on an embodiment of thepresent disclosure.

FIG. 17 shows wireless devices, based on an embodiment of the presentdisclosure.

FIG. 18 shows a signal process circuit for a transmission signal, basedon an embodiment of the present disclosure.

FIG. 19 shows another example of a wireless device, based on anembodiment of the present disclosure.

FIG. 20 shows a hand-held device, based on an embodiment of the presentdisclosure.

FIG. 21 shows a vehicle or an autonomous vehicle, based on an embodimentof the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

In the present specification, “A or B” may mean “only A”, “only B” or“both A and B.” In other words, in the present specification, “A or B”may be interpreted as “A and/or B”. For example, in the presentspecification, “A, B, or C” may mean “only A”, “only B”, “only C”, or“any combination of A, B, C”.

A slash (/) or comma used in the present specification may mean“and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B”may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C”may mean “A, B, or C”.

In the present specification, “at least one of A and B” may mean “onlyA”, “only B”, or “both A and B”. In addition, in the presentspecification, the expression “at least one of A or B” or “at least oneof A and/or B” may be interpreted as “at least one of A and B”.

In addition, in the present specification, “at least one of A, B, and C”may mean “only A”, “only B”, “only C”, or “any combination of A, B, andC”. In addition, “at least one of A, B, or C” or “at least one of A, B,and/or C” may mean “at least one of A, B, and C”.

In addition, a parenthesis used in the present specification may mean“for example”. Specifically, when indicated as “control information(PDCCH)”, it may mean that “PDCCH” is proposed as an example of the“control information”. In other words, the “control information” of thepresent specification is not limited to “PDCCH”, and “PDCCH” may beproposed as an example of the “control information”. In addition, whenindicated as “control information (i.e., PDCCH)”, it may also mean that“PDCCH” is proposed as an example of the “control information”.

A technical feature described individually in one figure in the presentspecification may be individually implemented, or may be simultaneouslyimplemented.

The technology described below may be used in various wirelesscommunication systems such as code division multiple access (CDMA),frequency division multiple access (FDMA), time division multiple access(TDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and so on. TheCDMA may be implemented with a radio technology, such as universalterrestrial radio access (UTRA) or CDMA-2000. The TDMA may beimplemented with a radio technology, such as global system for mobilecommunications (GSM)/general packet ratio service (GPRS)/enhanced datarate for GSM evolution (EDGE). The OFDMA may be implemented with a radiotechnology, such as institute of electrical and electronics engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA(E-UTRA), and so on. IEEE 802.16m is an evolved version of IEEE 802.16eand provides backward compatibility with a system based on the IEEE802.16e. The UTRA is part of a universal mobile telecommunication system(UMTS). 3rd generation partnership project (3GPP) long term evolution(LTE) is part of an evolved UMTS (E-UMTS) using the E-UTRA. The 3GPP LTEuses the OFDMA in a downlink and uses the SC-FDMA in an uplink.LTE-advanced (LTE-A) is an evolution of the LTE.

5G NR is a successive technology of LTE-A corresponding to a newClean-slate type mobile communication system having the characteristicsof high performance, low latency, high availability, and so on. 5G NRmay use resources of all spectrum available for usage including lowfrequency bands of less than 1 GHz, middle frequency bands ranging from1 GHz to 10 GHz, high frequency (millimeter waves) of 24 GHz or more,and so on.

For clarity in the description, the following description will mostlyfocus on LTE-A or 5G NR. However, technical features according to anembodiment of the present disclosure will not be limited only to this.

FIG. 2 shows a structure of an NR system, based on an embodiment of thepresent disclosure. The embodiment of FIG. 2 may be combined withvarious embodiments of the present disclosure.

Referring to FIG. 2 , a next generation-radio access network (NG-RAN)may include a BS 20 providing a UE 10 with a user plane and controlplane protocol termination. For example, the BS 20 may include a nextgeneration-Node B (gNB) and/or an evolved-NodeB (eNB). For example, theUE 10 may be fixed or mobile and may be referred to as other terms, suchas a mobile station (MS), a user terminal (UT), a subscriber station(SS), a mobile terminal (MT), wireless device, and so on. For example,the BS may be referred to as a fixed station which communicates with theUE 10 and may be referred to as other terms, such as a base transceiversystem (BTS), an access point (AP), and so on.

The embodiment of FIG. 2 exemplifies a case where only the gNB isincluded. The BSs 20 may be connected to one another via Xn interface.The BS 20 may be connected to one another via 5th generation (5G) corenetwork (5GC) and NG interface. More specifically, the BSs 20 may beconnected to an access and mobility management function (AMF) 30 viaNG-C interface, and may be connected to a user plane function (UPF) 30via NG-U interface.

Layers of a radio interface protocol between the UE and the network canbe classified into a first layer (layer 1, L1), a second layer (layer 2,L2), and a third layer (layer 3, L3) based on the lower three layers ofthe open system interconnection (OSI) model that is well-known in thecommunication system. Among them, a physical (PHY) layer belonging tothe first layer provides an information transfer service by using aphysical channel, and a radio resource control (RRC) layer belonging tothe third layer serves to control a radio resource between the UE andthe network. For this, the RRC layer exchanges an RRC message betweenthe UE and the BS.

FIG. 3 shows a radio protocol architecture, based on an embodiment ofthe present disclosure. The embodiment of FIG. 3 may be combined withvarious embodiments of the present disclosure. Specifically, (a) of FIG.3 shows a radio protocol stack of a user plane for Uu communication, and(b) of FIG. 3 shows a radio protocol stack of a control plane for Uucommunication. (c) of FIG. 3 shows a radio protocol stack of a userplane for SL communication, and (d) of FIG. 3 shows a radio protocolstack of a control plane for SL communication.

Referring to FIG. 3 , a physical layer provides an upper layer with aninformation transfer service through a physical channel. The physicallayer is connected to a medium access control (MAC) layer which is anupper layer of the physical layer through a transport channel. Data istransferred between the MAC layer and the physical layer through thetransport channel. The transport channel is classified according to howand with what characteristics data is transmitted through a radiointerface.

Between different physical layers, i.e., a physical layer of atransmitter and a physical layer of a receiver, data are transferredthrough the physical channel. The physical channel is modulated using anorthogonal frequency division multiplexing (OFDM) scheme, and utilizestime and frequency as a radio resource.

The MAC layer provides services to a radio link control (RLC) layer,which is a higher layer of the MAC layer, via a logical channel. The MAClayer provides a function of mapping multiple logical channels tomultiple transport channels. The MAC layer also provides a function oflogical channel multiplexing by mapping multiple logical channels to asingle transport channel. The MAC layer provides data transfer servicesover logical channels.

The RLC layer performs concatenation, segmentation, and reassembly ofRadio Link Control Service Data Unit (RLC SDU). In order to ensurediverse quality of service (QoS) required by a radio bearer (RB), theRLC layer provides three types of operation modes, i.e., a transparentmode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM).An AM RLC provides error correction through an automatic repeat request(ARQ).

A radio resource control (RRC) layer is defined only in the controlplane. The RRC layer serves to control the logical channel, thetransport channel, and the physical channel in association withconfiguration, reconfiguration and release of RBs. The RB is a logicalpath provided by the first layer (i.e., the physical layer or the PHYlayer) and the second layer (i.e., a MAC layer, an RLC layer, a packetdata convergence protocol (PDCP) layer, and a service data adaptationprotocol (SDAP) layer) for data delivery between the UE and the network.

Functions of a packet data convergence protocol (PDCP) layer in the userplane include user data delivery, header compression, and ciphering.Functions of a PDCP layer in the control plane include control-planedata delivery and ciphering/integrity protection.

A service data adaptation protocol (SDAP) layer is defined only in auser plane. The SDAP layer performs mapping between a Quality of Service(QoS) flow and a data radio bearer (DRB) and QoS flow ID (QFI) markingin both DL and UL packets.

The configuration of the RB implies a process for specifying a radioprotocol layer and channel properties to provide a particular serviceand for determining respective detailed parameters and operations. TheRB can be classified into two types, i.e., a signaling RB (SRB) and adata RB (DRB). The SRB is used as a path for transmitting an RRC messagein the control plane. The DRB is used as a path for transmitting userdata in the user plane.

When an RRC connection is established between an RRC layer of the UE andan RRC layer of the E-UTRAN, the UE is in an RRC_CONNECTED state, and,otherwise, the UE may be in an RRC_IDLE state. In case of the NR, anRRC_INACTIVE state is additionally defined, and a UE being in theRRC_INACTIVE state may maintain its connection with a core networkwhereas its connection with the BS is released.

Data is transmitted from the network to the UE through a downlinktransport channel Examples of the downlink transport channel include abroadcast channel (BCH) for transmitting system information and adownlink-shared channel (SCH) for transmitting user traffic or controlmessages. Traffic of downlink multicast or broadcast services or thecontrol messages can be transmitted on the downlink-SCH or an additionaldownlink multicast channel (MCH). Data is transmitted from the UE to thenetwork through an uplink transport channel. Examples of the uplinktransport channel include a random access channel (RACH) fortransmitting an initial control message and an uplink SCH fortransmitting user traffic or control messages.

Examples of logical channels belonging to a higher channel of thetransport channel and mapped onto the transport channels include abroadcast channel (BCCH), a paging control channel (PCCH), a commoncontrol channel (CCCH), a multicast control channel (MCCH), a multicasttraffic channel (MTCH), etc.

FIG. 4 shows a structure of a radio frame of an NR, based on anembodiment of the present disclosure. The embodiment of FIG. 4 may becombined with various embodiments of the present disclosure.

Referring to FIG. 4 , in the NR, a radio frame may be used forperforming uplink and downlink transmission. A radio frame has a lengthof 10 ms and may be defined to be configured of two half-frames (HFs). Ahalf-frame may include five 1 ms subframes (SFs). A subframe (SF) may bedivided into one or more slots, and the number of slots within asubframe may be determined based on subcarrier spacing (SCS). Each slotmay include 12 or 14 OFDM(A) symbols according to a cyclic prefix (CP).

In case of using a normal CP, each slot may include 14 symbols. In caseof using an extended CP, each slot may include 12 symbols. Herein, asymbol may include an OFDM symbol (or CP-OFDM symbol) and a SingleCarrier-FDMA (SC-FDMA) symbol (or Discrete Fourier Transform-spread-OFDM(DFT-s-OFDM) symbol).

Table 1 shown below represents an example of a number of symbols perslot (N^(slot) _(symb)), a number slots per frame (N^(frame,u) _(slot)),and a number of slots per subframe (N^(subframe,u) _(slot)) based on anSCS configuration (u), in a case where a normal CP is used.

TABLE 1 SCS (15*2^(u)) N^(slot) _(symb) N^(frame, u) _(slot)N^(subframe, u) _(slot) 15 KHz (u = 0) 14 10 1 30 KHz (u = 1) 14 20 2 60KHz (u = 2) 14 40 4 120 KHz (u = 3)  14 80 8 240 KHz (u = 4)  14 160 16

Table 2 shows an example of a number of symbols per slot, a number ofslots per frame, and a number of slots per subframe based on the SCS, ina case where an extended CP is used.

TABLE 2 SCS (15*2^(u)) N^(slot) _(symb) N^(frame, u) _(slot)N^(subframe, u) _(slot) 60 KHz (u = 2) 12 40 4

In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, and so on)between multiple cells being integrate to one UE may be differentlyconfigured. Accordingly, a (absolute time) duration (or section) of atime resource (e.g., subframe, slot or TTI) (collectively referred to asa time unit (TU) for simplicity) being configured of the same number ofsymbols may be differently configured in the integrated cells.

In the NR, multiple numerologies or SCSs for supporting diverse 5Gservices may be supported. For example, in case an SCS is 15 kHz, a widearea of the conventional cellular bands may be supported, and, in casean SCS is 30 kHz/60 kHz a dense-urban, lower latency, wider carrierbandwidth may be supported. In case the SCS is 60 kHz or higher, abandwidth that is greater than 24.25 GHz may be used in order toovercome phase noise.

An NR frequency band may be defined as two different types of frequencyranges. The two different types of frequency ranges may be FR1 and FR2.The values of the frequency ranges may be changed (or varied), and, forexample, the two different types of frequency ranges may be as shownbelow in Table 3. Among the frequency ranges that are used in an NRsystem, FR1 may mean a “sub 6 GHz range”, and FR2 may mean an “above 6GHz range” and may also be referred to as a millimeter wave (mmW).

TABLE 3 Frequency Range Corresponding frequency Subcarrier Spacingdesignation range (SCS) FR1  450 MHz-6000 MHz  15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

As described above, the values of the frequency ranges in the NR systemmay be changed (or varied). For example, as shown below in Table 4, FR1may include a band within a range of 410 MHz to 7125 MHz. Morespecifically, FR1 may include a frequency band of 6 GHz (or 5850, 5900,5925 MHz, and so on) and higher. For example, a frequency band of 6 GHz(or 5850, 5900, 5925 MHz, and so on) and higher being included in FR1mat include an unlicensed band. The unlicensed band may be used fordiverse purposes, e.g., the unlicensed band for vehicle-specificcommunication (e.g., automated driving).

TABLE 4 Frequency Range Corresponding frequency Subcarrier Spacingdesignation range (SCS) FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

FIG. 5 shows a structure of a slot of an NR frame, based on anembodiment of the present disclosure. The embodiment of FIG. 5 may becombined with various embodiments of the present disclosure.

Referring to FIG. 5 , a slot includes a plurality of symbols in a timedomain. For example, in case of a normal CP, one slot may include 14symbols. However, in case of an extended CP, one slot may include 12symbols. Alternatively, in case of a normal CP, one slot may include 7symbols. However, in case of an extended CP, one slot may include 6symbols.

A carrier includes a plurality of subcarriers in a frequency domain AResource Block (RB) may be defined as a plurality of consecutivesubcarriers (e.g., 12 subcarriers) in the frequency domain. A BandwidthPart (BWP) may be defined as a plurality of consecutive (Physical)Resource Blocks ((P)RBs) in the frequency domain, and the BWP maycorrespond to one numerology (e.g., SCS, CP length, and so on). Acarrier may include a maximum of N number BWPs (e.g., 5 BWPs). Datacommunication may be performed via an activated BWP. Each element may bereferred to as a Resource Element (RE) within a resource grid and onecomplex symbol may be mapped to each element.

Hereinafter, a bandwidth part (BWP) and a carrier will be described.

The BWP may be a set of consecutive physical resource blocks (PRBs) in agiven numerology. The PRB may be selected from consecutive sub-sets ofcommon resource blocks (CRBs) for the given numerology on a givencarrier

For example, the BWP may be at least any one of an active BWP, aninitial BWP, and/or a default BWP. For example, the UE may not monitordownlink radio link quality in a DL BWP other than an active DL BWP on aprimary cell (PCell). For example, the UE may not receive PDCCH,physical downlink shared channel (PDSCH), or channel stateinformation—reference signal (CSI-RS) (excluding RRM) outside the activeDL BWP. For example, the UE may not trigger a channel state information(CSI) report for the inactive DL BWP. For example, the UE may nottransmit physical uplink control channel (PUCCH) or physical uplinkshared channel (PUSCH) outside an active UL BWP. For example, in adownlink case, the initial BWP may be given as a consecutive RB set fora remaining minimum system information (RMSI) control resource set(CORESET) (configured by physical broadcast channel (PBCH)). Forexample, in an uplink case, the initial BWP may be given by systeminformation block (SIB) for a random access procedure. For example, thedefault BWP may be configured by a higher layer. For example, an initialvalue of the default BWP may be an initial DL BWP. For energy saving, ifthe UE fails to detect downlink control information (DCI) during aspecific period, the UE may switch the active BWP of the UE to thedefault BWP.

Meanwhile, the BWP may be defined for SL. The same SL BWP may be used intransmission and reception. For example, a transmitting UE may transmitan SL channel or an SL signal on a specific BWP, and a receiving UE mayreceive the SL channel or the SL signal on the specific BWP. In alicensed carrier, the SL BWP may be defined separately from a Uu BWP,and the SL BWP may have configuration signaling separate from the UuBWP. For example, the UE may receive a configuration for the SL BWP fromthe BS/network. For example, the UE may receive a configuration for theUu BWP from the BS/network. The SL BWP may be (pre-)configured in acarrier with respect to an out-of-coverage NR V2X UE and an RRC_IDLE UE.For the UE in the RRC_CONNECTED mode, at least one SL BWP may beactivated in the carrier.

FIG. 6 shows an example of a BWP, based on an embodiment of the presentdisclosure. The embodiment of FIG. 6 may be combined with variousembodiments of the present disclosure. It is assumed in the embodimentof FIG. 6 that the number of BWPs is 3.

Referring to FIG. 6 , a common resource block (CRB) may be a carrierresource block numbered from one end of a carrier band to the other endthereof. In addition, the PRB may be a resource block numbered withineach BWP. A point A may indicate a common reference point for a resourceblock grid.

The BWP may be configured by a point A, an offset N^(start) _(BWP) fromthe point A, and a bandwidth N^(size) _(BWP). For example, the point Amay be an external reference point of a PRB of a carrier in which asubcarrier 0 of all numerologies (e.g., all numerologies supported by anetwork on that carrier) is aligned. For example, the offset may be aPRB interval between a lowest subcarrier and the point A in a givennumerology. For example, the bandwidth may be the number of PRBs in thegiven numerology.

Hereinafter, V2X or SL communication will be described.

A sidelink synchronization signal (SLSS) may include a primary sidelinksynchronization signal (PSSS) and a secondary sidelink synchronizationsignal (SSSS), as an SL-specific sequence. The PSSS may be referred toas a sidelink primary synchronization signal (S-PSS), and the SSSS maybe referred to as a sidelink secondary synchronization signal (S-SSS).For example, length-127 M-sequences may be used for the S-PSS, andlength-127 gold sequences may be used for the S-SSS. For example, a UEmay use the S-PSS for initial signal detection and for synchronizationacquisition. For example, the UE may use the S-PSS and the S-SSS foracquisition of detailed synchronization and for detection of asynchronization signal ID.

A physical sidelink broadcast channel (PSBCH) may be a (broadcast)channel for transmitting default (system) information which must befirst known by the UE before SL signal transmission/reception. Forexample, the default information may be information related to SLSS, aduplex mode (DM), a time division duplex (TDD) uplink/downlink (UL/DL)configuration, information related to a resource pool, a type of anapplication related to the SLSS, a subframe offset, broadcastinformation, or the like. For example, for evaluation of PSBCHperformance, in NR V2X, a payload size of the PSBCH may be 56 bitsincluding 24-bit cyclic redundancy check (CRC).

The S-PSS, the S-SSS, and the PSBCH may be included in a block format(e.g., SL synchronization signal (SS)/PSBCH block, hereinafter,sidelink-synchronization signal block (S-SSB)) supporting periodicaltransmission. The S-SSB may have the same numerology (i.e., SCS and CPlength) as a physical sidelink control channel (PSCCH)/physical sidelinkshared channel (PSSCH) in a carrier, and a transmission bandwidth mayexist within a (pre-)configured sidelink (SL) BWP. For example, theS-SSB may have a bandwidth of 11 resource blocks (RBs). For example, thePSBCH may exist across 11 RBs. In addition, a frequency position of theS-SSB may be (pre-)configured. Accordingly, the UE does not have toperform hypothesis detection at frequency to discover the S-SSB in thecarrier.

FIG. 7 shows a UE performing V2X or SL communication, based on anembodiment of the present disclosure. The embodiment of FIG. 7 may becombined with various embodiments of the present disclosure.

Referring to FIG. 7 , in V2X or SL communication, the term ‘UE’ maygenerally imply a UE of a user. However, if a network equipment such asa BS transmits/receives a signal according to a communication schemebetween UEs, the BS may also be regarded as a sort of the UE. Forexample, a UE 1 may be a first apparatus 100, and a UE 2 may be a secondapparatus 200.

For example, the UE 1 may select a resource unit corresponding to aspecific resource in a resource pool which implies a set of series ofresources. In addition, the UE 1 may transmit an SL signal by using theresource unit. For example, a resource pool in which the UE 1 is capableof transmitting a signal may be configured to the UE 2 which is areceiving UE, and the signal of the UE 1 may be detected in the resourcepool.

Herein, if the UE 1 is within a connectivity range of the BS, the BS mayinform the UE 1 of the resource pool. Otherwise, if the UE 1 is out ofthe connectivity range of the BS, another UE may inform the UE 1 of theresource pool, or the UE 1 may use a pre-configured resource pool.

In general, the resource pool may be configured in unit of a pluralityof resources, and each UE may select a unit of one or a plurality ofresources to use it in SL signal transmission thereof.

Hereinafter, resource allocation in SL will be described.

FIG. 8 shows a procedure of performing V2X or SL communication by a UEbased on a transmission mode, based on an embodiment of the presentdisclosure. The embodiment of FIG. 8 may be combined with variousembodiments of the present disclosure. In various embodiments of thepresent disclosure, the transmission mode may be called a mode or aresource allocation mode. Hereinafter, for convenience of explanation,in LTE, the transmission mode may be called an LTE transmission mode. InNR, the transmission mode may be called an NR resource allocation mode.

For example, (a) of FIG. 8 shows a UE operation related to an LTEtransmission mode 1 or an LTE transmission mode 3. Alternatively, forexample, (a) of FIG. 8 shows a UE operation related to an NR resourceallocation mode 1. For example, the LTE transmission mode 1 may beapplied to general SL communication, and the LTE transmission mode 3 maybe applied to V2X communication.

For example, (b) of FIG. 8 shows a UE operation related to an LTEtransmission mode 2 or an LTE transmission mode 4. Alternatively, forexample, (b) of FIG. 8 shows a UE operation related to an NR resourceallocation mode 2.

Referring to (a) of FIG. 8 , in the LTE transmission mode 1, the LTEtransmission mode 3, or the NR resource allocation mode 1, a BS mayschedule an SL resource to be used by the UE for SL transmission. Forexample, the BS may perform resource scheduling to a UE 1 through aPDCCH (e.g., downlink control information (DCI)) or RRC signaling (e.g.,Configured Grant Type 1 or Configured Grant Type 2), and the UE 1 mayperform V2X or SL communication with respect to a UE 2 according to theresource scheduling. For example, the UE 1 may transmit a sidelinkcontrol information (SCI) to the UE 2 through a physical sidelinkcontrol channel (PSCCH), and thereafter transmit data based on the SCIto the UE 2 through a physical sidelink shared channel (PSSCH).

Referring to (b) of FIG. 8 , in the LTE transmission mode 2, the LTEtransmission mode 4, or the NR resource allocation mode 2, the UE maydetermine an SL transmission resource within an SL resource configuredby a BS/network or a pre-configured SL resource. For example, theconfigured SL resource or the pre-configured SL resource may be aresource pool. For example, the UE may autonomously select or schedule aresource for SL transmission. For example, the UE may perform SLcommunication by autonomously selecting a resource within a configuredresource pool. For example, the UE may autonomously select a resourcewithin a selective window by performing a sensing and resource(re)selection procedure. For example, the sensing may be performed inunit of subchannels. In addition, the UE 1 which has autonomouslyselected the resource within the resource pool may transmit the SCI tothe UE 2 through a PSCCH, and thereafter may transmit data based on theSCI to the UE 2 through a PSSCH.

FIG. 9 shows three cast types, based on an embodiment of the presentdisclosure. The embodiment of FIG. 9 may be combined with variousembodiments of the present disclosure. Specifically, (a) of FIG. 9 showsbroadcast-type SL communication, (b) of FIG. 9 shows unicast type-SLcommunication, and (c) of FIG. 9 shows groupcast-type SL communication.In case of the unicast-type SL communication, a UE may performone-to-one communication with respect to another UE. In case of thegroupcast-type SL transmission, the UE may perform SL communication withrespect to one or more UEs in a group to which the UE belongs. Invarious embodiments of the present disclosure, SL groupcastcommunication may be replaced with SL multicast communication, SLone-to-many communication, or the like.

Meanwhile, in the present disclosure, for example, a transmitting UE (TXUE) may be a UE which transmits data to a (target) receiving UE (RX UE).For example, the TX UE may be a UE which performs PSCCH transmissionand/or PSSCH transmission. Additionally/alternatively, for example, theTX UE may be a UE which transmits SL CSI-RS(s) and/or a SL CSI reportrequest indicator to the (target) RX UE. Additionally/alternatively, forexample, the TX UE may be a UE which transmits a (control) channel(e.g., PSCCH, PSSCH, etc.) and/or reference signal(s) on the (control)channel (e.g., DM-RS, CSI-RS, etc.), to be used for a SL radio linkmonitoring (RLM) operation and/or a SL radio link failure (RLF)operation of the (target) RX UE.

Meanwhile, in the present disclosure, for example, a receiving UE (RXUE) may be a UE which transmits SL HARQ feedback to a transmitting UE(TX UE) based on whether decoding of data received from the TX UE issuccessful and/or whether detection/decoding of a PSCCH (related toPSSCH scheduling) transmitted by the TX UE is successful.Additionally/alternatively, for example, the RX UE may be a UE whichperforms SL CSI transmission to the TX UE based on SL CSI-RS(s) and/or aSL CSI report request indicator received from the TX UE.Additionally/alternatively, for example, the RX UE is a UE whichtransmits a SL (L1) reference signal received power (RSRP) measurementvalue, to the TX UE, measured based on (pre-defined) reference signal(s)and/or a SL (L1) RSRP report request indicator received from the TX UE.Additionally/alternatively, for example, the RX UE may be a UE whichtransmits data of the RX UE to the TX UE. Additionally/alternatively,for example, the RX UE may be a UE which performs a SL RLM operationand/or a SL RLF operation based on a (pre-configured) (control) channeland/or reference signal(s) on the (control) channel received from the TXUE.

Meanwhile, in the present disclosure, for example, in case the RX UEtransmits SL HARQ feedback information for a PSSCH and/or a PSCCHreceived from the TX UE, the following options or some of the followingoptions may be considered. Herein, for example, the following options orsome of the following options may be limitedly applied only if the RX UEsuccessfully decodes/detects a PSCCH scheduling a PSSCH.

(1) groupcast option 1: no acknowledgement (NACK) information may betransmitted to the TX UE only if the RX UE fails to decode/receive thePSSCH received from the TX UE.

(2) groupcast option 2: If the RX UE succeeds in decoding/receiving thePSSCH received from the TX UE, ACK information may be transmitted to theTX UE, and if the RX UE fails to decode/receive the PSSCH, NACKinformation may be transmitted to the TX UE.

Meanwhile, in the present disclosure, for example, the TX UE maytransmit the following information or some of the following informationto the RX UE through SCI(s). Herein, for example, the TX UE may transmitsome or all of the following information to the RX UE through a firstSCI and/or a second SCI.

-   -   PSSCH (and/or PSCCH) related resource allocation information        (e.g., the location/number of time/frequency resources, resource        reservation information (e.g., period))    -   SL CSI report request indicator or SL (L1) reference signal        received power (RSRP) (and/or SL (L1) reference signal received        quality (RSRQ) and/or SL (L1) reference signal strength        indicator (RSSI)) report request indicator    -   SL CSI transmission indicator (or SL (L1) RSRP (and/or SL (L1)        RSRQ and/or SL (L1) RSSI) information transmission indicator)        (on a PSSCH)    -   Modulation and Coding Scheme (MCS) information    -   TX power information    -   L1 destination ID information and/or L1 source ID information    -   SL HARQ process ID information    -   New Data Indicator (NDI) information    -   Redundancy Version (RV) information    -   (Transmission traffic/packet related) QoS information (e.g.,        priority information)    -   SL CSI-RS transmission indicator or information on the number of        antenna ports for (transmitting) SL CSI-RS    -   TX UE location information or location (or distance range)        information of the target RX UE (for which SL HARQ feedback is        requested)    -   Reference signal (e.g., DM-RS, etc.) information related to        decoding (and/or channel estimation) of data transmitted through        a PSSCH. For example, information related to a pattern of        (time-frequency) mapping resources of DM-RS(s), RANK        information, antenna port index information, information on the        number of antenna ports, etc.

Meanwhile, in the present disclosure, for example, since the TX UE maytransmit a SCI, a first SCI and/or a second SCI to the RX UE through aPSCCH, the PSCCH may be replaced/substituted with the SCI and/or thefirst SCI and/or the second SCI. Additionally/alternatively, the SCI maybe replaced/substituted with the PSCCH and/or the first SCI and/or thesecond SCI. Additionally/alternatively, for example, since the TX UE maytransmit a second SCI to the RX UE through a PSSCH, the PSSCH may bereplaced/substituted with the second SCI.

Meanwhile, in the present disclosure, for example, if SCI configurationfields are divided into two groups in consideration of a (relatively)high SCI payload size, the first SCI including a first SCI configurationfield group may be referred to as a 1^(st) SCI, and the second SCIincluding a second SCI configuration field group may be referred to as a2^(nd) SCI. Also, for example, the 1^(st) SCI may be transmitted to thereceiving UE through a PSCCH. Also, for example, the 2^(nd) SCI may betransmitted to the receiving UE through a (independent) PSCCH or may bepiggybacked and transmitted together with data through a PSSCH.

Meanwhile, in the present disclosure, for example, the term“configure/configured” or the term “define/defined” may refer to(pre)configuration from a base station or a network (through pre-definedsignaling (e.g., SIB, MAC, RRC, etc.)) (for each resource pool).

Meanwhile, in the present disclosure, for example, since an RLF may bedetermined based on out-of-synch (OOS) indicator(s) or in-synch (IS)indicator(s), the RLF may be replaced/substituted with out-of-synch(OOS) indicator(s) or in-synch (IS) indicator(s).

Meanwhile, in the present disclosure, for example, an RB may bereplaced/substituted with a subcarrier. Also, in the present disclosure,for example, a packet or a traffic may be replaced/substituted with a TBor a MAC PDU based on a transmission layer.

Meanwhile, in the present disclosure, a CBG may be replaced/substitutedwith a TB.

Meanwhile, in the present disclosure, for example, a source ID may bereplaced/substituted with a destination ID.

Meanwhile, in the present disclosure, for example, an L1 ID may bereplaced/substituted with an L2 ID. For example, the L1 ID may be an L1source ID or an L1 destination ID. For example, the L2 ID may be an L2source ID or an L2 destination ID.

Meanwhile, in the present disclosure, for example, an operation of thetransmitting UE to reserve/select/determine retransmission resource(s)may include: an operation of the transmitting UE toreserve/select/determine potential retransmission resource(s) for whichactual use will be determined based on SL HARQ feedback informationreceived from the receiving UE.

Meanwhile, in the present disclosure, a sub-selection window may bereplaced/substituted with a selection window and/or the pre-configurednumber of resource sets within the selection window, or vice versa.

Meanwhile, in the present disclosure, SL MODE 1 may refer to a resourceallocation method or a communication method in which a base stationdirectly schedules SL transmission resource(s) for a TX UE throughpre-defined signaling (e.g., DCI or RRC message). For example, SL MODE 2may refer to a resource allocation method or a communication method inwhich a UE independently selects SL transmission resource(s) in aresource pool pre-configured or configured from a base station or anetwork. For example, a UE performing SL communication based on SL MODE1 may be referred to as a MODE 1 UE or MODE 1 TX UE, and a UE performingSL communication based on SL MODE 2 may be referred to as a MODE 2 UE orMODE 2 TX UE.

Meanwhile, in the present disclosure, for example, a dynamic grant (DG)may be replaced/substituted with a configured grant (CG) and/or asemi-persistent scheduling (SPS) grant, or vice versa. For example, theDG may be replaced/substituted with a combination of the CG and the SPSgrant, or vice versa. For example, the CG may include at least one of aconfigured grant (CG) type 1 and/or a configured grant (CG) type 2. Forexample, in the CG type 1, a grant may be provided by RRC signaling andmay be stored as a configured grant. For example, in the CG type 2, agrant may be provided by a PDCCH, and may be stored or deleted as aconfigured grant based on L1 signaling indicating activation ordeactivation of the grant.

Meanwhile, in the present disclosure, a channel may bereplaced/substituted with a signal, or vice versa. For example,transmission/reception of a channel may include transmission/receptionof a signal. For example, transmission/reception of a signal may includetransmission/reception of a channel. In addition, for example, cast maybe replaced/substituted with at least one of unicast, groupcast, and/orbroadcast, or vice versa. For example, a cast type may bereplaced/substituted with at least one of unicast, groupcast, and/orbroadcast, or vice versa.

Meanwhile, in the present disclosure, a resource may bereplaced/substituted with a slot or a symbol, or vice versa. Forexample, the resource may include a slot and/or a symbol.

Meanwhile, in the present disclosure, a priority may bereplaced/substituted with at least one of logical channel prioritization(LCP), latency, reliability, minimum required communication range, proseper-packet priority (PPPP), sidelink radio bearer (SLRB), QoS profile,QoS parameter and/or requirement, or vice versa.

Meanwhile, in various embodiments of the present disclosure, thereservation resource and/or the selection resource may bereplaced/substituted with a sidelink grant (SL GRANT).

Meanwhile, in various embodiments of the present disclosure, latency maybe replaced/substituted with a packet delay budget (PDB).

Meanwhile, in various embodiments of the present disclosure, a messagefor triggering a report on sidelink channel state information/sidelinkchannel quality information (hereinafter, SL_CSI information) may bereplaced/substituted with a sidelink channel state information referencesignal (CSI-RS) reception.

Meanwhile, in the present disclosure, blind retransmission may referthat the TX UE performs retransmission without receiving SL HARQfeedback information from the RX UE. For example, SL HARQ feedback-basedretransmission may refer that the TX UE determines whether to performretransmission based on SL HARQ feedback information received from theRX UE. For example, if the TX UE receives NACK and/or DTX informationfrom the RX UE, the TX UE may perform retransmission to the RX UE.

Meanwhile, in the present disclosure, for example, for convenience ofdescription, a (physical) channel used when a RX UE transmits at leastone of the following information to a TX UE may be referred to as aPSFCH.

SL HARQ Feedback, SL CSI, SL (L1) RSRP

Meanwhile, in the present disclosure, a Uu channel may include a ULchannel and/or a DL channel. For example, the UL channel may include aPUSCH, a PUCCH, a sounding reference Signal (SRS), etc. For example, theDL channel may include a PDCCH, a PDSCH, a PSS/SSS, etc. For example, aSL channel may include a PSCCH, a PSSCH, a PSFCH, a PSBCH, a PSSS/SSSS,etc.

Meanwhile, in the present disclosure, sidelink information may includeat least one of a sidelink message, a sidelink packet, a sidelinkservice, sidelink data, sidelink control information, and/or a sidelinktransport block (TB). For example, sidelink information may betransmitted through a PSSCH and/or a PSCCH.

Meanwhile, in NR V2X communication or NR sidelink communication, atransmitting UE may reserve/select one or more transmission resourcesfor sidelink transmission (e.g., initial transmission and/orretransmission), and the transmitting UE may transmit information on thelocation of the one or more transmission resources to receiving UE(s).

Meanwhile, when performing sidelink communication, a method for atransmitting UE to reserve or pre-determine transmission resource(s) forreceiving UE(s) may be representatively as follows.

For example, the transmitting UE may perform a reservation oftransmission resource(s) based on a chain. Specifically, for example, ifthe transmitting UE reserves K transmission resources, the transmittingUE may transmit location information for less than K transmissionresources to receiving UE(s) through a SCI transmitted to the receivingUE(s) at any (or specific) transmission time or a time resource. Thatis, for example, the SCI may include location information for less thanthe K transmission resources. Alternatively, for example, if thetransmitting UE reserves K transmission resources related to a specificTB, the transmitting UE may transmit location information for less thanK transmission resources to receiving UE(s) through a SCI transmitted tothe receiving UE(s) at any (or specific) transmission time or a timeresource. That is, the SCI may include location information for lessthan the K transmission resources. In this case, for example, it ispossible to prevent performance degradation due to an excessive increasein payloads of the SCI, by signaling only the location information forless than K transmission resources to the receiving UE(s) through oneSCI transmitted at any (or specific) transmission time or the timeresource by the transmitting UE.

FIG. 10 shows a method in which a UE that has reserved transmissionresource(s) informs another UE of the transmission resource(s), based onan embodiment of the present disclosure. The embodiment of FIG. 10 maybe combined with various embodiments of the present disclosure.

Specifically, for example, (a) of FIG. 10 shows a method for performingby a transmitting UE chain-based resource reservation bytransmitting/signaling location information of (maximum) 2 transmissionresources to receiving UE(s) through one SCI, in the case of a value ofK=4. For example, (b) of FIG. 10 shows a method for performing by atransmitting UE chain-based resource reservation bytransmitting/signaling location information of (maximum) 3 transmissionresources to receiving UE(s) through one SCI, in the case of a value ofK=4. For example, referring to (a) and (b) of FIG. 10 , the transmittingUE may transmit/signal only location information of the fourthtransmission-related resource to the receiving UE(s) through the fourth(or last) transmission-related PSCCH. For example, referring to (a) ofFIG. 10 , the transmitting UE may transmit/signal to the receiving UE(s)not only location information of the fourth transmission-relatedresource but also location information of the third transmission-relatedresource additionally through the fourth (or last) transmission-relatedPSCCH. For example, referring to (b) of FIG. 10 , the transmitting UEmay transmit/signal to the receiving UE(s) not only location informationof the fourth transmission-related resource but also locationinformation of the second transmission-related resource and locationinformation of the third transmission-related resource additionallythrough the fourth (or last) transmission-related PSCCH. In this case,for example, in (a) and (b) of FIG. 10 , if the transmitting UE maytransmit/signal to the receiving UE(s) only location information of thefourth transmission-related resource through the fourth (or last)transmission-related PSCCH, the transmitting UE may set or designate afield/bit of location information of unused or remaining transmissionresource(s) to a pre-configured value (e.g., 0). For example, in (a) and(b) of FIG. 10 , if the transmitting UE may transmit/signal to thereceiving UE(s) only location information of the fourthtransmission-related resource through the fourth (or last)transmission-related PSCCH, the transmitting UE may be set or designatea field/bit of location information of unused or remaining transmissionresource(s) to a pre-configured status/bit value indicating/representingthe last transmission (among 4 transmissions).

Meanwhile, for example, the transmitting UE may perform a reservation oftransmission resource(s) based on a block. Specifically, for example, ifthe transmitting UE reserves K transmission resources, the transmittingUE may transmit location information for K transmission resources toreceiving UE(s) through a SCI transmitted to the receiving UE(s) at any(or specific) transmission time or a time resource. That is, the SCI mayinclude location information for K transmission resources. For example,if the transmitting UE reserves K transmission resources related to aspecific TB, the transmitting UE may transmit location information for Ktransmission resources to receiving UE(s) through a SCI transmitted tothe receiving UE(s) at any (or specific) transmission time or a timeresource. That is, the SCI may include location information for Ktransmission resources. For example, (c) of FIG. 10 shows a method forperforming by the transmitting UE block-based resource reservation, bysignaling location information of 4 transmission resources to receivingUE(s) through one SCI, in the case of a value of K=4.

Meanwhile, for example, according to rules defined in 3GPP TS 38.321document, the location of transmission resources related to mode 1 SL CGType-1 and/or mode 2 CG Type-2 may be determined.

Based on an embodiment of the present disclosure, for example, in orderto determine the location of transmission resources related to mode 1 SLCG type-1 and/or mode 2 CG type-2, an SFN 0-based slot offset value maybe counted based on SL logical slots (e.g., SL numerology unit). Forexample, the SFN 0-based slot offset value (i.e., SL-TIMEOFFSETCG-TYPE1)may be counted based on SL logical slots belonging to a target resourcepool. For example, the UE may count the SFN 0-based slot offset value(i.e., SL-TIMEOFFSETCG-TYPE1) based on SL logical slots belonging to thetarget resource pool. For example, this counting scheme may be referredto as option A. For example, an SFN 0-based slot offset value may becounted based on UL slots (e.g., Uu numerology unit) to which a resourcepool bitmap can be applied. For example, the SFN 0-based slot offsetvalue (i.e., SL-TIMEOFFSETCG-TYPE1) may be counted based on UL slots, DLslots, or Uu slots (e.g., Uu numerology) to which a resource pool bitmapcan be applied. For example, the UE may count the SFN 0-based slotoffset value (i.e., SL-TIMEOFFSETCG-TYPE1) based on UL slots, DL slots,or Uu slots (e.g., Uu numerology) to which the resource pool bitmap canbe applied. This counting scheme may be referred to as option B. Herein,for example, the numerology may include sub-carrier spacing and CPlength. Herein, for example, the first transmission resource (i.e., 1sttransmission resource) determined based on SL-TIMEOFFSETCG-TYPE1 may bea resource belonging to a target resource pool of a mode 1 SL grant. Forexample, the UE may determine the first transmission resource based onSL-TIMEOFFSETCG-TYPE1 as the resource belonging to the target resourcepool of the SL grant.

Also, for example, in the case of the option B, the first transmissionresource may be located in a SL slot of a target resource pool whichoccurs first in the time domain after SL-TIMEOFFSETCG-TYPE1. Forexample, the UE may determine the first transmission resource in the SLslot of the target resource pool which occurs first in the time domainafter SL-TIMEOFFSETCG-TYPE1.

For example, in various embodiments of the present disclosure, “FRAME”may be defined as the pre-configured number of SL slots belonging to aresource pool (e.g., 10 or 10*SL SCS/15). For example, in variousembodiments of the present disclosure, “FRAME” may be defined as thepre-configured number of UL slots, DL slots, or Uu slots to which aresource pool bitmap can be applied (e.g., 10 or 10*Uu SCS/15). Forexample, in various embodiments of the present disclosure, “FRAME” maybe “FRAME” in the equation.

For example, after the first transmission resource related to mode 1 SLCG type-1 and/or mode 1 SL CG type-2 is determined based on the rules ofvarious embodiments of the present disclosure, subsequent transmissionresources may be considered to occur in a period defined byPERIODICITYSL number of SL slots based on the location of the firsttransmission resource within the target resource pool. For example,PERIODICITYSL may be a number based on the pre-configured equation. Forexample, after the UE determines the first transmission resource relatedto mode 1 SL CG type-1 and/or mode 1 SL CG type-2 based on the rules ofvarious embodiments of the present disclosure, subsequent transmissionresources may occur repeatedly in a period defined by PERIODICITYSLnumber of SL slots based on the location of the first transmissionresource within the target resource pool.

Tables 5 and 6 below show methods for determining the location oftransmission resources related to sidelink mode 1 SL CG type-1 or mode 2CG type-2.

TABLE 5 5.8.3  Sidelink There are two types of transmission withoutdynamic grant:  - configured grant Type 1 where an sidelink grant isprovided by RRC, and stored as configured sidelink grant;  - configuredgrant Type 2 where an sidelink grant is provided by PDCCH, and stored orcleared as configured sidelink grant based on L1 signalling indicatingconfigured sidelink grant activation or deactivation. Type 1 and/or Type2 are configured with a single BWP. Multiple configurations of up to 8configured grants (including both Type 1 and Type 2, if configured) canbe active simultaneously on the BWP. RRC configures the followingparameters when the configured grant Type 1 is configured, as specifiedin TS 38.331 [5] or TS 36.331 [21]:  - sl-ConfigIndexCG: the identifierof a configured grant for sidelink;  - sl-CS-RNTI: SLCS-RNTI forretransmission;  - sl-NrOfHARQ-Processes: the number of HARQ processesfor configured grant;  - sl-PeriodCG: periodicity of the configuredgrant Type 1;  - sl-TimeOffsetCG-Type1: Offset of a resource withrespect to SFN = 0 in time domain, refering to the number of logicalslots that can be used for SL transmission;  - sl-TimeResourceCG-Type1:time resource location of the configured grant Type 1;  -sl-CG-MaxTransNumList: the maximum number of times that a TB can betransmitted using the configured grant;  - sl-HARQ-ProcID-offset: offsetof HARQ process for configured grant Type 1. RRC configures thefollowing parameters when the configured grant Type 2 is configured, asspecified in TS 38.331 [5]:  - sl-ConfigIndexCG: the identifier of aconfigured grant for sidelink;  - sl-CS-RNTI: SLCS-RNTI for activation,deactivation, and retransmission;  - sl-NrOfHARQ-Processes: the numberof HARQ processes for configured grant;  - sl-PeriodCG: periodicity ofthe configured grant Type 2;  - sl-CG-MaxTransNumList: the maximumnumber of times that a TB can be transmitted using the configured grant; - sl-HARQ-ProcID-offset: offset of HARQ process for configured grantType 2.

TABLE 6 Upon configuration of a configured grant Type 1, the MAC entityshall for each configured sidelink grant:   1> store the sidelink grantprovided by RRC as a configured sidelink   grant;   1> initialise orre-initialise the configured sidelink grant to determine   PSCCHduration(s) and PSSCH duration(s) according to sl-   TimeOffsetCG-Type1and sl-TimeResourceCG-Type1, and to   reoccur with sl-periodCG fortransmissions of multiple MAC PDUs   according to clause 8.1.2 of TS38.214 [7].   NOTE 1: If the MAC entity is configured with multipleconfigured   sidelink grants, collision among the configured sidelinkgrants may   occur. How to handle the collision is left to UEimplementation. After a sidelink grant is configured for a configuredgrant Type 1, the MAC entity shall consider sequentially that the firstslot of the S^(th) sidelink grant occurs in the logical slot for which:[(SFN × numberOfSLSlotsPerFrame) + logical slot number in the frame] =(numberOfSLSlotsPerFrame + sl-TimeOffsetCG-Type1+ S × PeriodicitySL)modulo (1024 × numberOfSLSlotsPerFrame).${{{where}{PeriodicitySL}} = \left\lceil {\frac{N}{20{ms}} \times {sl\_ periodCG}} \right\rceil},{{and}N{refers}{to}{the}}$number of slots that can be used for SL transmission within 20ms, ifconfigured, of TDD-UL-DL-ConfigCommon as specified in TS 38.331 [5] andclause 8.1.7 of TS 38.214 [7], and numberOfSLSlotsPerFrame refers to thenumber of logical slots that can be used for SL transmission. After asidelink grant is configured for a configured grant Type 2, the MACentity shall consider sequentially that the first slot of S^(th)sidelink grant occurs in the logical slot for which: [(SFN ×numberOfSLSlotsPerFrame) + logical slot number in the frame] =[(SFN_(start time) × numberOfSLSlotsPerFrame + slot_(start time)) + S ×PeriodicitySL] modulo (1024 × numberOfSLSlotsPerFrame). whereSFN_(start time) and slot_(start time) are the SFN and logical slot,respectively, of the first transmission opportunity of PSSCH where theconfigured sidelink grant was (re-)initialised.

Based on an embodiment of the present disclosure, when a MAC PDU istransmitted by using a HARQ feedback method for which NACK is onlytransmitted (hereinafter referred to as NACK ONLY HARQ feedback method)based on a distance between a transmitting UE and a receiving UE(hereinafter referred to as TX-RX distance), if location information ofthe transmitting UE becomes unavailable, the transmitting UE may beconfigured to transmit the same MAC PDU by using a NACK ONLY HARQfeedback method that does not consider the distance between thetransmitting UE and the receiving UE. For example, when the MAC PDU istransmitted by using the TX-RX distance-based NACK ONLY HARQ feedbackmethod, if the location information of the transmitting UE becomesunavailable, the transmitting UE may transmit the same MAC PDU by usingthe NACK ONLY HARQ feedback method that does not consider the distancebetween the transmitting UE and the receiving UE.

For example, when a MAC PDU is transmitted by using the TX-RXdistance-based NACK ONLY HARQ feedback method, if the locationinformation of the transmitting UE becomes unavailable, the transmittingUE may be configured to transmit the same MAC PDU by using a HARQfeedback method for which ACK or NACK is transmitted without consideringthe distance between the transmitting UE and the receiving UE(hereinafter referred to as ACK/NACK HARQ feedback method). For example,when the MAC PDU is transmitted by using the TX-RX distance-based NACKONLY HARQ feedback method, if the location information of thetransmitting UE becomes unavailable, the transmitting UE may transmitthe same MAC PDU by using the ACK/NACK HARQ feedback method that doesnot consider the distance between the transmitting UE and the receivingUE.

For example, when a MAC PDU is transmitted by using the TX-RXdistance-based NACK ONLY HARQ feedback method, location information ofthe transmitting UE may become unavailable. For example, in this case,if group size information and/or a group member ID of the transmittingUE is provided from an upper layer of the transmitting UE, and if thenumber of PSFCH candidate resources associated with PSSCH transmissionwithin a resource pool is greater than or equal to the group size, thetransmitting UE may transmit the same MAC PDU by using the NACK ONLYHARQ feedback method that does not consider the distance between thetransmitting UE and the receiving UE. For example, in this case, ifgroup size information and/or a group member ID of the transmitting UEis provided from an upper layer of the transmitting UE, and if thenumber of PSFCH candidate resources associated with PSSCH transmissionwithin a resource pool is greater than or equal to the group size, thetransmitting UE may transmit the same MAC PDU by using the ACK/NACK HARQfeedback method that does not consider the distance between thetransmitting UE and the receiving UE.

Herein, for example, if location information of the transmitting UE forretransmission related to the MAC PDU is changed from the location ofthe transmitting UE for the first/initial transmission related to theMAC PDU, the transmitting UE may include the updated locationinformation in the retransmission.

Also, for example, the receiving UE may receive the first/initialtransmission related to the MAC PDU from the transmitting UE in theTX-RX distance-based NACK ONLY HARQ feedback method, and the receivingUE may receive retransmission of the same MAC PDU. In this case, forexample, if location information of the receiving UE is changed, thereceiving UE may be configured to use its own location information atthe time of receiving the first/initial transmission when calculatingthe TX-RX distance for determining whether or not to transmit NACK ONLYHARQ feedback. In this case, for example, if location information of thereceiving UE is changed, the receiving UE may be configured to useupdated location information of the receiving UE at the time ofreceiving retransmission when calculating the TX-RX distance fordetermining whether or not to transmit NACK ONLY HARQ feedback. In thiscase, for example, if location information of the receiving UE ischanged, the receiving UE may be configured to use its own locationinformation at the time of receiving the first/initial transmission andupdated location information at the time of receiving retransmissionwhen calculating the TX-RX distance for determining whether or not totransmit NACK ONLY HARQ feedback.

Herein, for example, when the receiving UE calculates a value for theTX-RX distance, location information of the transmitting UE used by thereceiving UE may be set to location information of the transmitting UEfor the first/initial transmission. For example, when the receiving UEcalculates a value for the TX-RX distance, location information of thetransmitting UE used by the receiving UE may be set to locationinformation of the transmitting UE for retransmission. For example, whenthe receiving UE calculates a value for the TX-RX distance, locationinformation of the transmitting UE used by the receiving UE may be setto at least one of location information of the transmitting UE for thefirst initial transmission or location information of the transmittingUE for retransmission. For example, the receiving UE may be a receivingUE receiving retransmission. That is, for example, when the receiving UEreceiving retransmission calculates a value for the TX-RX distance,location information of the transmitting UE used by the receiving UE maybe set to location information of the transmitting UE used in thefirst/initial transmission.

Based on an embodiment of the present disclosure, for example, when SLHARQ feedback information related to a PSFCH is transmitted through aPUCCH, if the number of PSSCH slots associated with a PSFCH is changed,a codebook size related to SL HARQ feedback information transmittedthrough a PUCCH may be changed according to the number of PSSCH slots.For example, when SL HARQ feedback information related to thepre-configured number of PSFCHs is transmitted through a PUCCH, if thenumber of PSSCHs and/or PSCCH slots associated with the correspondingPSFCH is changed in the time domain, the number of bits or thesemi-static codebook size related to SL HARQ feedback informationtransmitted through a PUCCH may change according to the changed numberof associated PSSCHs and/or PSCCH slots. For example, when the UEtransmits SL HARQ feedback information related to the pre-configurednumber of PSFCHs to the base station through a PUCCH, if the number ofPSSCH and/or PSCCH slots associated with the corresponding PSFCH ischanged in the time domain, the number of bits or the semi-staticcodebook size related to SL HARQ feedback information transmittedthrough a PUCCH may be changed according to the changed number of PSSCHand/or PSCCH slots.

Based on an embodiment of the present disclosure, for example, in casethat the transmitting UE performs HARQ feedback request-based initialtransmission for a MAC PDU based on an allocated mode 1 resource, a timegap between the time of receiving a PSFCH and the time of anadditionally allocated mode 1 retransmission resource (hereinafter,RRSC_ADD) may be smaller than a minimum processing time that can besupported by the UE. In this case, for example, the transmitting UE mayskip/omit the retransmission operation on RRSC_ADD. In this case, forexample, the transmitting UE may drop the related MAC PDU on RRSC_ADD.In this case, for example, the transmitting UE may perform blindretransmission (e.g., retransmission that does not request HARQfeedback) on RRSC_ADD.

For example, in case that the transmitting UE performs HARQ feedbackrequest-based initial transmission and/or retransmission for a MAC PDUbased on allocated mode 1 resources, a time gap between the time whenthe transmitting UE receives a PSFCH and the time when RRSC_ADD isadditionally allocated for the same MAC PDU may be smaller than aminimum processing time that can be supported by the UE. In this case,for example, the transmitting UE may skip/omit the retransmissionoperation on RRSC_ADD. In this case, for example, the transmitting UEmay drop the related MAC PDU on RRSC_ADD. In this case, for example, thetransmitting UE may perform blind retransmission (e.g., retransmissionthat does not request HARQ feedback) on RRSC_ADD.

For example, based on various rules of the present disclosure, if a TDDU/D configuration is not configured, it may be configured to deriveTDD-CONFIG information in a PSBCH. For example, based on the rulesdescribed in Table 7, if the TDD U/D configuration is not configure, itmay be configured to derive a UL resource (e.g., slot) to which aresource pool bitmap is applied. For example, the resource pool bitmapmay be pre-configured.

Table 7 below describes rules for determining a bit sequence ofsl-TDD-Config in a PSBCH when tdd-UL-DL-ConfigurationCommon orsl-TDD-Configuration is not provided. For example, iftdd-UL-DL-ConfigurationCommon (e.g., SIB1) or sl-TDD-Configuration(e.g., pre-configuration) is not provided, it is necessary to clarifyhow the UE determines the bit sequence of sl-TDD-Config (i.e., a0, a1,a2, a3, . . . , a11) in the PSBCH or the assumption about the ULresource to which the resource pool bitmap is applied.

TABLE 7 We think that the following two aspects should be clarified forthe case when tdd-UL-DL- ConfigurationCommon (e.g., SIB1) orsl-TDD-Configuration (e.g., Pre-configuration) is not provided.Otherwise, SL sync operation would not be supported correctly becausedifferent UEs' behaviours are not aligned. • Issue A) How a UEdetermines a bit sequence (i.e., a₀, a₁, a₂, a₃, ..., a₁₁) ofsl-TDD-Config in PSBCH? • Issue B) Assumption of UL resources to whichthe resource pool bitmap is applied? The following rule can be appliedto determine a bit sequence of sl-TDD-Config in PSBCH when tdd-UL-DL-ConfigurationCommon or sl-TDD-Configuration is not provided. With thisapproach, it could be possible to support SFNed TX of PSBCHs amongdifferent UEs having the same sync source (e.g., gNB, GNSS). Also thereis no need to use the reserved bit states remained for the usage offuture release. • a₀ (i.e., pattern number): - 0 (i.e., single pattern)(and/or 1 (i.e., two patterns)) • a₁,a₂,a₃,a₄ (i.e., pattern period): -0,0,1,0 (i.e., 1ms) (and/or 1,0,0,0 (i.e., 10ms) and/or (pre)configuredpattern period )  ✓ Note that 1ms (or 10ms) is the smallest (or largest)value of periods that can used for all the SCS cases •a₅,a₆,a₇,a₈,a₉,a₁₀,a₁₁ (i.e., UL slot number): - All the slotsdetermined by “a₀“, “a₁,a₂,a₃,a₄“ and “SL SCS” are indicated as UL(and/or “a₅,a₆,a₇ a₈,a₉,a₁₀,a₁₁” is set to “1,1,1,1,1,1,1”) For Issue Bin Q1, for example, it can be defined that a UE assumes a virtual TDDconfiguration with one pattern with 1ms (and/or 10ms) period (and/or(pre)configured period) and all the symbols/slots designated as UL. TheSCS of virtual TDD configuration is SL SCS. Note that UL slots ofvirtual TDD configuration are the same as those of sl-TDD-Configindicated by PSBCH in Issue A.

Based on the rules of Table 7, PSBCH transmission can be supportedbetween different UEs having the same synchronization source (e.g., gNB,GNSS). Also, for example, there may be no need to use the remainingreserved bit states. Referring to Table 7, herein, for example, a0(i.e., a pattern number) may be 0 (i.e., a single pattern) or 1 (i.e.,two patterns). Herein, for example, a1, a2, a3, a4 (i.e., patternperiod) may be 0, 0, 1, 0 (i.e., 1 ms) or 1, 0, 0, 0 (i.e., 10 ms) or aconfigured pattern period. Herein, for example, the configured patternperiod may be pre-configured. For example, 1 ms may be the smallestperiod value that can be used for all SCS cases. For example, 10 ms maybe the largest period value that can be used for all SCS cases. Herein,for example, in a5, a6, a7, a8, a9, a10, all (i.e., UL slot number), allslots determined by “a0”, “a1, a2, a3, a4” and “SL SCS” may berepresented as UL. For example, “a5, a6, a7, a8, a9, a10, a11” may beset to “1, 1, 1, 1, 1, 1, 1”. For example, it may be defined that the UEassumes a virtual TDD configuration with one pattern having 1 ms and allsymbols/slots designated as UL. For example, it may be defined that theUE assumes a virtual TDD configuration with one pattern having 10 ms andall symbols/slots designated as UL. For example, it may be defined thatthe UE assumes a virtual TDD configuration with one pattern having aconfigured period and all symbols/slots designated as UL. For example,the configured period may be pre-configured. For example, SCS of thevirtual TDD configuration may be SL SCS. For example, a UL slot of thevirtual TDD configuration may be the same as a UL slot of sl-TDD-Configindicated by a PSBCH.

Based on an embodiment of the present disclosure, for example, areference Uu DCI format used for size alignment with DCI format 3_0 maybe designated as one requiring a smaller number of zero-padding bitsamong Uu DCI 0_1 and UU DCI 0_2. For example, a reference Uu DCI formatused for size alignment with DCI format 3_0 may be designated as onerequiring a smaller number of zero-padding bits among at least one of UuDCI 0_1 or Uu DCI 0_0 and UU DCI 0_2. For example, the UE may determinea reference Uu DCI format used for size alignment with DCI format 3_0 asone requiring a smaller number of zero-padding bits among at least oneof Uu DCI 0_1 or Uu DCI 0_0 and UU DCI 0_2. Herein, for example, thereference Uu DCI format may be transmitted on USS. For example, thereference Uu DCI format may be transmitted on CSS. For example, thereference Uu DCI format may be a fallback Uu DCI format. For example,the reference Uu DCI format may be a non-fallback Uu DCI format.

Additionally, for example, a transferred sidelink grant and relatedsidelink transmission information may be associated with a sidelinkprocess. For example, each sidelink process may support one TB. Forexample, for each sidelink grant, a sidelink HARQ entity may perform thefollowing operation.

For example, the sidelink HARQ entity may select positive-negativeacknowledgment or negative-only acknowledgment. That is, for example,selection of positive-negative acknowledgment or negative-onlyacknowledgment may be UE implementation. In this case, for example, theUE may select negative-only acknowledgment. For example, if the UEselects negative-only acknowledgment, location information of the UE maybe available, and sl-TransRange may be configured for a logical channelof a MAC PDU, and sl-ZoneConfig may be configured. Herein, for example,sl-TransRange may indicate a communication range requirement. Forexample, sl-ZoneConfig may indicate zone configuration.

For example, the sidelink HARQ entity may determine a value ofsl-ZoneLength corresponding to a communication range requirement, andmay set Zone_id to a value of Zone_id calculated using the determinedvalue of sl-ZoneLength. For example, sl-ZoneLength may indicate thelength of each geographic zone.

For example, the sidelink HARQ entity may transfer the MAC PDU, asidelink grant, and sidelink transmission information of the TB to therelated sidelink process.

For example, in case of retransmission, the sidelink HARQ entity maytransfer a sidelink grant of the MAC PDU to the related sidelinkprocess.

For example, for each PSSCH period in which transmission for a sidelinkprocess occurs, one TB and related HARQ information may be received fromthe sidelink HARQ entity.

For example, if SCI indicates negative-only acknowledgment, locationinformation of the UE may be available, and the distance between thelocation of the UE and the central of the closest zone calculated basedon Zone_id in SCI and the value of sl-ZoneLength corresponding to thecommunication range requirement of SCI may be smaller than or equal tothe communication range requirement of SCI.

FIG. 11 shows a procedure for transmitting, by a transmitting UE, SCIincluding location information of the transmitting UE and a MAC PDU to areceiving UE, based on an embodiment of the present disclosure. FIG. 13shows an example in which the location of a transmitting UE is changed,based on an embodiment of the present disclosure. The embodiments ofFIGS. 11 and 13 may be combined with various embodiments of the presentdisclosure.

Referring to FIG. 11 , in step S1110, the transmitting UE may transmitfirst sidelink control information (SCI) related to initial transmissionto the receiving UE through a first physical sidelink control channel(PSCCH). For example, the first SCI related to initial transmission mayinclude scheduling information of second SCI related to initialtransmission transmitted through a first physical sidelink sharedchannel (PSSCH) related to the first PSCCH.

In step S1120, the transmitting UE may transmit the second SCI and amedium access control (MAC) protocol data unit (PDU) related to initialtransmission to the receiving UE through the first PSSCH. For example,the second SCI related to initial transmission may include locationinformation of the transmitting UE related to initial transmission. Forexample, a distance between the transmitting UE and the receiving UE maybe calculated based on location information of the transmitting UErelated to initial transmission.

Additionally, for example, the location information of the transmittingUE may include a zone ID of the transmitting UE. For example, thereceiving UE may calculate the distance between the transmitting UE andthe receiving UE based on the zone ID of the transmitting UE.

In step S1130, the transmitting UE may transmit first SCI related toretransmission to the receiving UE through a second PSCCH. For example,the first SCI related to retransmission may include schedulinginformation of second SCI related to retransmission transmitted througha second PSSCH related to the second PSCCH.

In step S1140, the transmitting UE may transmit the second SCI and a MACPDU related to retransmission to the receiving UE through the secondPSSCH. For example, the second SCI related to retransmission may includelocation information of the transmitting UE related to initialtransmission.

For example, the transmitting UE may transmit the second SCI related toretransmission to the receiving UE through the second PSSCH, and thetransmitting UE may perform blind retransmission for the MAC PDU to thereceiving UE. That is, for example, the transmitting UE may performblind retransmission for the MAC PDU to the receiving UE withoutreceiving HARQ feedback from the receiving UE.

For example, based on the change in location information of thetransmitting UE, the second SCI related to retransmission may includelocation information of the transmitting UE related to retransmission.

Referring to FIG. 13 , for example, in case that the transmitting UE islocated in the zone A, the transmitting UE may transmit SCI includinglocation information of the zone A and a MAC PDU to the receiving UEthrough a PSSCH. Then, for example, if the location of the transmittingUE is changed from the zone A to the zone B, the transmitting UE maystill retransmit SCI including location information of the zone A and aMAC PDU to the receiving UE through a PSSCH.

FIG. 12 shows another procedure for transmitting, by a transmitting UE,SCI including location information of the transmitting UE and a MAC PDUto a receiving UE, based on an embodiment of the present disclosure. Theembodiment of FIG. 12 may be combined with various embodiments of thepresent disclosure. FIG. 12 may be combined with various embodiments ofthe present disclosure.

Referring to FIG. 12 , in step S1210, the transmitting UE may transmitfirst SCI related to initial transmission to the receiving UE through afirst PSCCH. For example, the first SCI related to initial transmissionmay include scheduling information of second SCI related to initialtransmission transmitted through a first PSSCH related to the firstPSCCH.

In step S1220, the transmitting UE may transmit the second SCI and a MACPDU related to initial transmission to the receiving UE through thefirst PSSCH. For example, the second SCI related to initial transmissionmay include location information of the transmitting UE related toinitial transmission. For example, a distance between the transmittingUE and the receiving UE may be calculated based on location informationof the transmitting UE related to initial transmission.

For example, a method of HARQ NACK-only feedback may be enabled. Forexample, the method of HARQ NACK-only feedback may be enabled for thetransmitting UE or the receiving UE. For example, the method of HARQNACK-only feedback may be a method of transmitting NACK information tothe transmitting UE only when the receiving UE fails to decode/receive aPSSCH received from the transmitting UE.

For example, an HARQ feedback method not based on a distance between thetransmitting UE and the receiving UE may be configured based on thatlocation information of the transmitting UE is not available. Forexample, the HARQ feedback method may be a HARQ NACK-only feedbackmethod. For example, the HARQ feedback method may be an ACK or NACKfeedback method. For example, the ACK or NACK feedback method may be amethod in which the receiving UE transmits ACK information to thetransmitting UE if the receiving UE succeeds in decoding/receiving aPSSCH received from the transmitting UE, and the receiving UE transmitsNACK information to the transmitting UE if the receiving UE fails todecode/receive a PSSCH received from the transmitting UE.

Additionally, for example, the location information of the transmittingUE may include a zone ID of the transmitting UE. For example, thereceiving UE may calculate the distance between the transmitting UE andthe receiving UE based on the zone ID of the transmitting UE.

In step S1230, the transmitting UE may receive HARQ NACK for the MAC PDUfrom the receiving UE. For example, the transmitting UE may receive HARQNACK for the MAC PDU from the receiving UE through a PSFCH.

In step S1240, the transmitting UE may transmit first SCI related toretransmission to the receiving UE through a second PSCCH. For example,the first SCI related to retransmission may include schedulinginformation of second SCI related to retransmission transmitted througha second PSSCH related to the second PSCCH.

In step S1250, the transmitting UE may transmit the second SCI and a MACPDU related to retransmission to the receiving UE through the secondPSSCH. For example, the second SCI related to retransmission may includelocation information of the transmitting UE related to initialtransmission. For example, based on that the transmitting UE receivesthe HARQ NACK, the transmitting UE may transmit the second SCI and theMAC PDU related to retransmission to the receiving UE through the secondPSSCH.

Referring to FIG. 13 , for example, if the transmitting UE is located inthe zone A, the transmitting UE may transmit SCI including locationinformation of the zone A and a MAC PDU to the receiving UE through aPSSCH. For example, if the location of the transmitting UE is changedfrom the zone A to the zone B, and if the transmitting UE receives HARQNACK from the receiving UE, the transmitting UE may still retransmit SCIincluding location information of the zone A and a MAC PDU to thereceiving UE through a PSSCH.

Alternatively, for example, if the location of the transmitting UE ischanged from the zone A to the zone B, and if the transmitting UEreceives HARQ NACK from the receiving UE, the transmitting UE mayretransmit SCI including location information of the zone B and a MACPDU to the receiving UE through a PSSCH.

Alternatively, for example, if the location of the transmitting UE ischanged from the zone A to the zone B, and if the transmitting UEreceives HARQ NACK from the receiving UE, the transmitting UE mayretransmit SCI including location information of the zone A and locationinformation of the zone B, and a MAC PDU to the receiving UE through aPSSCH.

For example, a method of HARQ NACK-only feedback may be based on adistance between the transmitting UE and the receiving UE. For example,the distance between the transmitting UE and the receiving UE may becalculated based on location information of the transmitting UE relatedto initial transmission.

For example, based on the change in location information of thetransmitting UE, second SCI related to retransmission may includelocation information of the transmitting UE related to retransmission.

For example, based on that location information of the receiving UE ischanged, second SCI related to retransmission may include locationinformation of the transmitting UE related to initial transmission.Herein, for example, information indicating that location information ofthe receiving UE is changed may be included in HARQ NACK. For example,based on the change in location information of the receiving UE, atleast one of the location of the receiving UE related to initialtransmission or the location of the second device related toretransmission may be used to calculate the distance between thetransmitting UE and the receiving UE.

FIG. 14 shows a method for a first device to transmit SCI includinglocation information and a MAC PDU to a second device, based on anembodiment of the present disclosure. The embodiment of FIG. 14 may becombined with various embodiments of the present disclosure.

Referring to FIG. 14 , in step S1410, the first device 100 may transmitfirst sidelink control information (SCI) related to initial transmissionto the second device 200 through a first physical sidelink controlchannel (PSCCH). For example, the first SCI related to initialtransmission may include scheduling information of second SCI related toinitial transmission transmitted through a first physical sidelinkshared channel (PSSCH) related to the first PSCCH.

In step S1420, the first device 100 may transmit the second SCI relatedto initial transmission and a medium access control (MAC) protocol dataunit (PDU) to the second device 200 through the first PSSCH. Forexample, the second SCI related to initial transmission may includelocation information of the first device 100 related to initialtransmission.

In step S1430, the first device 100 may transmit first SCI related toretransmission to the second device 200 through a second PSCCH. Forexample, the first SCI related to retransmission may include schedulinginformation of second SCI related to retransmission transmitted througha second PSSCH related to the second PSCCH.

In step S1440, the first device 100 may transmit the second SCI relatedto retransmission and the MAC PDU to the second device 200 through thesecond PSSCH. For example, the second SCI related to retransmission mayinclude the location information related to initial transmission of thefirst device 100.

For example, based on that the first device 100 receives HARQ NACK fromthe second device 200, the MAC PDU may be retransmitted.

For example, a method of HARQ NACK-only feedback may be enabled. Forexample, the method of HARQ NACK-only feedback may be based on adistance between the first device 100 and the second device 200. Forexample, the distance between the first device 100 and the second device200 may be calculated based on the location information related toinitial transmission of the first device 100.

For example, based on that location information of the second device 200is changed, the second SCI related to retransmission may include thelocation information related to initial transmission of the first device100.

For example, based on that location information of the second device 200is changed, at least one of the location of the second device 200related to initial transmission or the location of the second device 200related to retransmission may be used to calculate the distance betweenthe first device 100 and the second device 200.

For example, an HARQ feedback method not based on the distance betweenthe first device 100 and the second device 200 may be configured basedon that location information of the first device 100 is not available.For example, the HARQ feedback method may be a method of HARQ NACK-onlyfeedback. For example, the HARQ feedback method may be a method of ACKor NACK feedback. For example, at least one of group size informationmay be received, and the number of PSFCH candidate resources in aresource pool related to the HARQ feedback may be greater than or equalto the group size.

For example, the MAC PDU may be blindly retransmitted.

For example, TDD-configuration information on a PSBCH based on apre-configured rule may be determined based on that a time duplexdivision (TDD) UL-DL configuration is not configured.

The above-described embodiment can be applied to various the device(s)described below. For example, the processor 102 of the first device 100may control the transceiver 106 to transmit first sidelink controlinformation (SCI) related to initial transmission to the second device200 through a first physical sidelink control channel (PSCCH). Inaddition, for example, the processor 102 of the first device 100 maycontrol the transceiver 106 to transmit second SCI related to initialtransmission and a medium access control (MAC) protocol data unit (PDU)through the first PSSCH. In addition, for example, the processor 102 ofthe first device 100 may control the transceiver 106 to transmit firstSCI related to retransmission to the second device 200 through a secondPSCCH. In addition, for example, the processor 102 of the first device100 may control the transceiver 106 to transmit second SCI related toretransmission and the MAC PDU to the second device 200 through thesecond PSSCH.

Based on an embodiment of the present disclosure, a first device adaptedto perform wireless communication may be provided. For example, thefirst device may comprise: one or more memories storing instructions;one or more transceivers; and one or more processors connected to theone or more memories and the one or more transceivers. For example, theone or more processors may execute the instructions to: transmit, to asecond device, first sidelink control information (SCI) related toinitial transmission through a first physical sidelink control channel(PSCCH), wherein the first SCI related to the initial transmissionincludes scheduling information of second SCI related to the initialtransmission transmitted through a first physical sidelink sharedchannel (PSSCH) related to the first PSCCH; transmit, to the seconddevice, the second SCI related to the initial transmission and a mediumaccess control (MAC) protocol data unit (PDU) through the first PSSCH,wherein the second SCI related to the initial transmission includeslocation information related to the initial transmission of the firstdevice; transmit, to the second device, first SCI related toretransmission through a second PSCCH, wherein the first SCI related tothe retransmission includes scheduling information of second SCI relatedto the retransmission transmitted through a second PSSCH related to thesecond PSCCH; and transmit, to the second device, the second SCI relatedto the retransmission and the MAC PDU through the second PSSCH, whereinthe second SCI related to the retransmission includes the locationinformation related to the initial transmission of the first device.

Based on an embodiment of the present disclosure, an apparatus adaptedto control a first user equipment (UE) may be provided. For example, theapparatus may comprise: one or more processors; and one or more memoriesoperably connected to the one or more processors and storinginstructions. For example, the one or more processors may execute theinstructions to: transmit, to a second UE, first sidelink controlinformation (SCI) related to initial transmission through a firstphysical sidelink control channel (PSCCH), wherein the first SCI relatedto the initial transmission includes scheduling information of secondSCI related to the initial transmission transmitted through a firstphysical sidelink shared channel (PSSCH) related to the first PSCCH;transmit, to the second UE, the second SCI related to the initialtransmission and a medium access control (MAC) protocol data unit (PDU)through the first PSSCH, wherein the second SCI related to the initialtransmission includes location information related to the initialtransmission of the first UE; transmit, to the second UE, first SCIrelated to retransmission through a second PSCCH, wherein the first SCIrelated to the retransmission includes scheduling information of secondSCI related to the retransmission transmitted through a second PSSCHrelated to the second PSCCH; and transmit, to the second UE, the secondSCI related to the retransmission and the MAC PDU through the secondPSSCH, wherein the second SCI related to the retransmission includes thelocation information related to the initial transmission of the firstUE.

Based on an embodiment of the present disclosure, a non-transitorycomputer-readable storage medium storing instructions may be provided.For example, the instructions, when executed, may cause a first deviceto: transmit, to a second device, first sidelink control information(SCI) related to initial transmission through a first physical sidelinkcontrol channel (PSCCH), wherein the first SCI related to the initialtransmission includes scheduling information of second SCI related tothe initial transmission transmitted through a first physical sidelinkshared channel (PSSCH) related to the first PSCCH; transmit, to thesecond device, the second SCI related to the initial transmission and amedium access control (MAC) protocol data unit (PDU) through the firstPSSCH, wherein the second SCI related to the initial transmissionincludes location information related to the initial transmission of thefirst device; transmit, to the second device, first SCI related toretransmission through a second PSCCH, wherein the first SCI related tothe retransmission includes scheduling information of second SCI relatedto the retransmission transmitted through a second PSSCH related to thesecond PSCCH; and transmit, to the second device, the second SCI relatedto the retransmission and the MAC PDU through the second PSSCH, whereinthe second SCI related to the retransmission includes the locationinformation related to the initial transmission of the first device.

FIG. 15 shows a method for a second device to receive SCI includinglocation information a MAC PDU from a first device, based on anembodiment of the present disclosure. The embodiment of FIG. 15 may becombined with various embodiments of the present disclosure.

Referring to FIG. 15 , in step S1510, the second device 200 may receivefirst sidelink control information (SCI) related to initial transmissionfrom the first device 100 through a first physical sidelink controlchannel (PSCCH). For example, the first SCI related to initialtransmission may include scheduling information of second SCI related toinitial transmission transmitted through a first physical sidelinkshared channel (PSSCH) related to the first PSCCH.

In step S1520, the second device 200 may receive the second SCI relatedto initial transmission and a medium access control (MAC) protocol dataunit (PDU) from the first device 100 through the first PSSCH. Forexample, the second SCI related to initial transmission may includelocation information related to initial transmission of the firstdevice.

In step S1530, the second device 200 may receive first SCI related toretransmission from the first device 100 through a second PSCCH. Forexample, the first SCI related to retransmission may include schedulinginformation of second SCI related to retransmission transmitted througha second PSSCH related to the second PSCCH.

In step S1540, the second device 200 may receive the second SCI relatedto retransmission and a MAC PDU from the first device 100 through thesecond PSSCH. For example, the second SCI related to retransmission mayinclude location information related to initial transmission of thefirst device.

For example, based on that the first device 100 receives HARQ NACK fromthe second device 200, the MAC PDU may be retransmitted.

For example, a method of HARQ NACK-only feedback may be enabled. Forexample, the method of HARQ NACK-only feedback may be based on adistance between the first device 100 and the second device 200. Forexample, the distance between the first device 100 and the second device200 may be calculated based on the location information related toinitial transmission of the first device 100.

For example, based on that location information of the second device 200is changed, the second SCI related to retransmission may include thelocation information related to initial transmission of the first device100.

For example, based on that location information of the second device 200is changed, at least one of the location of the second device 200related to initial transmission or the location of the second device 200related to retransmission may be used to calculate the distance betweenthe first device 100 and the second device 200.

For example, an HARQ feedback method not based on the distance betweenthe first device 100 and the second device 200 may be configured basedon that location information of the first device 100 is not available.For example, the HARQ feedback method may be a method of HARQ NACK-onlyfeedback. For example, the HARQ feedback method may be a method of ACKor NACK feedback. For example, at least one of group size informationmay be received, and the number of PSFCH candidate resources in aresource pool related to the HARQ feedback may be greater than or equalto the group size.

For example, the MAC PDU may be blindly retransmitted.

For example, TDD-configuration information on a PSBCH based on apre-configured rule may be determined based on that a time duplexdivision (TDD) UL-DL configuration is not configured.

The above-described embodiment can be applied to various the device(s)described below. For example, the processor 202 of the second device 200may control the transceiver 206 to receive first sidelink controlinformation (SCI) related to initial transmission from the first device100 through a first physical sidelink control channel (PSCCH). Inaddition, for example, the processor 202 of the second device 200 maycontrol the transceiver 206 to receive second SCI related to initialtransmission and a medium access control (MAC) protocol data unit (PDU)from the first device 100 through the first PSSCH. In addition, forexample, the processor 202 of the second device 200 may control thetransceiver 206 to receive first SCI related to retransmission from thefirst device 100 through a second PSCCH. In addition, for example, theprocessor 202 of the second device 200 may control the transceiver 206to receive second SCI related to retransmission and the MAC PDU from thefirst device 100 through the second PSSCH.

Based on an embodiment of the present disclosure, a second deviceadapted to perform wireless communication may be provided. For example,the second device may comprise: one or more memories storinginstructions; one or more transceivers; and one or more processorsconnected to the one or more memories and the one or more transceivers.For example, the one or more processors may execute the instructions to:receive, from a first device, first sidelink control information (SCI)related to initial transmission through a first physical sidelinkcontrol channel (PSCCH), wherein the first SCI related to the initialtransmission includes scheduling information of second SCI related tothe initial transmission transmitted through a first physical sidelinkshared channel (PSSCH) related to the first PSCCH; receive, from thefirst device, the second SCI related to the initial transmission and amedium access control (MAC) protocol data unit (PDU) through the firstPSSCH, wherein the second SCI related to the initial transmissionincludes location information related to the initial transmission of thefirst device; receive, from the first device, first SCI related toretransmission through a second PSCCH, wherein the first SCI related tothe retransmission includes scheduling information of second SCI relatedto the retransmission transmitted through a second PSSCH related to thesecond PSCCH; and receive, from the first device, the second SCI relatedto the retransmission and the MAC PDU through the second PSSCH, whereinthe second SCI related to the retransmission includes the locationinformation related to the initial transmission of the first device.

Various embodiments of the present disclosure may be combined with eachother.

Hereinafter, device(s) to which various embodiments of the presentdisclosure can be applied will be described.

The various descriptions, functions, procedures, proposals, methods,and/or operational flowcharts of the present disclosure described inthis document may be applied to, without being limited to, a variety offields requiring wireless communication/connection (e.g., 5G) betweendevices.

Hereinafter, a description will be given in more detail with referenceto the drawings. In the following drawings/description, the samereference symbols may denote the same or corresponding hardware blocks,software blocks, or functional blocks unless described otherwise.

FIG. 16 shows a communication system 1, based on an embodiment of thepresent disclosure.

Referring to FIG. 16 , a communication system 1 to which variousembodiments of the present disclosure are applied includes wirelessdevices, Base Stations (BSs), and a network. Herein, the wirelessdevices represent devices performing communication using Radio AccessTechnology (RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE))and may be referred to as communication/radio/5G devices. The wirelessdevices may include, without being limited to, a robot 100 a, vehicles100 b-1 and 100 b-2, an eXtended Reality (XR) device 100 c, a hand-helddevice 100 d, a home appliance 100 e, an Internet of Things (IoT) device100 f, and an Artificial Intelligence (AI) device/server 400. Forexample, the vehicles may include a vehicle having a wirelesscommunication function, an autonomous vehicle, and a vehicle capable ofperforming communication between vehicles. Herein, the vehicles mayinclude an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR devicemay include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality(MR) device and may be implemented in the form of a Head-Mounted Device(HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, asmartphone, a computer, a wearable device, a home appliance device, adigital signage, a vehicle, a robot, etc. The hand-held device mayinclude a smartphone, a smartpad, a wearable device (e.g., a smartwatchor a smartglasses), and a computer (e.g., a notebook). The homeappliance may include a TV, a refrigerator, and a washing machine. TheIoT device may include a sensor and a smartmeter. For example, the BSsand the network may be implemented as wireless devices and a specificwireless device 200 a may operate as a BS/network node with respect toother wireless devices.

Here, wireless communication technology implemented in wireless devices100 a to 100 f of the present disclosure may include Narrowband Internetof Things for low-power communication in addition to LTE, NR, and 6G. Inthis case, for example, NB-IoT technology may be an example of Low PowerWide Area Network (LPWAN) technology and may be implemented as standardssuch as LTE Cat NB1, and/or LTE Cat NB2, and is not limited to the namedescribed above. Additionally or alternatively, the wirelesscommunication technology implemented in the wireless devices 100 a to100 f of the present disclosure may perform communication based on LTE-Mtechnology. In this case, as an example, the LTE-M technology may be anexample of the LPWAN and may be called by various names includingenhanced Machine Type Communication (eMTC), and the like. For example,the LTE-M technology may be implemented as at least any one of variousstandards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTEnon-Bandwidth Limited (non-BL), 5) LTE-MTC, 6) LTE Machine TypeCommunication, and/or 7) LTE M, and is not limited to the name describedabove. Additionally or alternatively, the wireless communicationtechnology implemented in the wireless devices 100 a to 100 f of thepresent disclosure may include at least one of Bluetooth, Low Power WideArea Network (LPWAN), and ZigBee considering the low-powercommunication, and is not limited to the name described above. As anexample, the ZigBee technology may generate personal area networks (PAN)related to small/low-power digital communication based on variousstandards including IEEE 802.15.4, and the like, and may be called byvarious names.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through the BSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. Vehicle-to-Vehicle(V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as uplink/downlinkcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, Integrated AccessBackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the present disclosure.

FIG. 17 shows wireless devices, based on an embodiment of the presentdisclosure.

Referring to FIG. 17 , a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through a variety of RATs (e.g.,LTE and NR). Herein, {the first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. 16 .

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store a variety of informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the present disclosure, the wireless devicemay represent a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process informationwithin the memory(s) 204 to generate third information/signals and thentransmit radio signals including the third information/signals throughthe transceiver(s) 206. The processor(s) 202 may receive radio signalsincluding fourth information/signals through the transceiver(s) 106 andthen store information obtained by processing the fourthinformation/signals in the memory(s) 204. The memory(s) 204 may beconnected to the processor(s) 202 and may store a variety of informationrelated to operations of the processor(s) 202. For example, thememory(s) 204 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 202 and the memory(s) 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 206 may be connected to the processor(s) 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the present disclosure, the wireless device may represent acommunication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more Protocol Data Units (PDUs) and/or one or more Service Data Unit(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by Read-OnlyMemories (ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable Read-Only Memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother devices. For example, the one or more transceivers 106 and 206 maybe connected to the one or more processors 102 and 202 and transmit andreceive radio signals. For example, the one or more processors 102 and202 may perform control so that the one or more transceivers 106 and 206may transmit user data, control information, or radio signals to one ormore other devices. The one or more processors 102 and 202 may performcontrol so that the one or more transceivers 106 and 206 may receiveuser data, control information, or radio signals from one or more otherdevices. The one or more transceivers 106 and 206 may be connected tothe one or more antennas 108 and 208 and the one or more transceivers106 and 206 may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, through the one ormore antennas 108 and 208. In this document, the one or more antennasmay be a plurality of physical antennas or a plurality of logicalantennas (e.g., antenna ports). The one or more transceivers 106 and 206may convert received radio signals/channels etc. from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc. using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels, etc.processed using the one or more processors 102 and 202 from the baseband signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters.

FIG. 18 shows a signal process circuit for a transmission signal, basedon an embodiment of the present disclosure.

Referring to FIG. 18 , a signal processing circuit 1000 may includescramblers 1010, modulators 1020, a layer mapper 1030, a precoder 1040,resource mappers 1050, and signal generators 1060. An operation/functionof FIG. 18 may be performed, without being limited to, the processors102 and 202 and/or the transceivers 106 and 206 of FIG. 17 . Hardwareelements of FIG. 18 may be implemented by the processors 102 and 202and/or the transceivers 106 and 206 of FIG. 17 . For example, blocks1010 to 1060 may be implemented by the processors 102 and 202 of FIG. 17. Alternatively, the blocks 1010 to 1050 may be implemented by theprocessors 102 and 202 of FIG. 17 and the block 1060 may be implementedby the transceivers 106 and 206 of FIG. 17 .

Codewords may be converted into radio signals via the signal processingcircuit 1000 of FIG. 18 . Herein, the codewords are encoded bitsequences of information blocks. The information blocks may includetransport blocks (e.g., a UL-SCH transport block, a DL-SCH transportblock). The radio signals may be transmitted through various physicalchannels (e.g., a PUSCH and a PDSCH).

Specifically, the codewords may be converted into scrambled bitsequences by the scramblers 1010. Scramble sequences used for scramblingmay be generated based on an initialization value, and theinitialization value may include ID information of a wireless device.The scrambled bit sequences may be modulated to modulation symbolsequences by the modulators 1020. A modulation scheme may includepi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying(m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complexmodulation symbol sequences may be mapped to one or more transportlayers by the layer mapper 1030. Modulation symbols of each transportlayer may be mapped (precoded) to corresponding antenna port(s) by theprecoder 1040. Outputs z of the precoder 1040 may be obtained bymultiplying outputs y of the layer mapper 1030 by an N*M precodingmatrix W. Herein, N is the number of antenna ports and M is the numberof transport layers. The precoder 1040 may perform precoding afterperforming transform precoding (e.g., DFT) for complex modulationsymbols. Alternatively, the precoder 1040 may perform precoding withoutperforming transform precoding.

The resource mappers 1050 may map modulation symbols of each antennaport to time-frequency resources. The time-frequency resources mayinclude a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMAsymbols) in the time domain and a plurality of subcarriers in thefrequency domain. The signal generators 1060 may generate radio signalsfrom the mapped modulation symbols and the generated radio signals maybe transmitted to other devices through each antenna. For this purpose,the signal generators 1060 may include Inverse Fast Fourier Transform(IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-AnalogConverters (DACs), and frequency up-converters.

Signal processing procedures for a signal received in the wirelessdevice may be configured in a reverse manner of the signal processingprocedures 1010 to 1060 of FIG. 18 . For example, the wireless devices(e.g., 100 and 200 of FIG. 17 ) may receive radio signals from theexterior through the antenna ports/transceivers. The received radiosignals may be converted into baseband signals through signal restorers.To this end, the signal restorers may include frequency downlinkconverters, Analog-to-Digital Converters (ADCs), CP remover, and FastFourier Transform (FFT) modules. Next, the baseband signals may berestored to codewords through a resource demapping procedure, apostcoding procedure, a demodulation processor, and a descramblingprocedure. The codewords may be restored to original information blocksthrough decoding. Therefore, a signal processing circuit (notillustrated) for a reception signal may include signal restorers,resource demappers, a postcoder, demodulators, descramblers, anddecoders.

FIG. 19 shows another example of a wireless device, based on anembodiment of the present disclosure. The wireless device may beimplemented in various forms according to a use-case/service (refer toFIG. 16 ).

Referring to FIG. 19 , wireless devices 100 and 200 may correspond tothe wireless devices 100 and 200 of FIG. 17 and may be configured byvarious elements, components, units/portions, and/or modules. Forexample, each of the wireless devices 100 and 200 may include acommunication unit 110, a control unit 120, a memory unit 130, andadditional components 140. The communication unit may include acommunication circuit 112 and transceiver(s) 114. For example, thecommunication circuit 112 may include the one or more processors 102 and202 and/or the one or more memories 104 and 204 of FIG. 17 . Forexample, the transceiver(s) 114 may include the one or more transceivers106 and 206 and/or the one or more antennas 108 and 208 of FIG. 17 . Thecontrol unit 120 is electrically connected to the communication unit110, the memory 130, and the additional components 140 and controlsoverall operation of the wireless devices. For example, the control unit120 may control an electric/mechanical operation of the wireless devicebased on programs/code/commands/information stored in the memory unit130. The control unit 120 may transmit the information stored in thememory unit 130 to the exterior (e.g., other communication devices) viathe communication unit 110 through a wireless/wired interface or store,in the memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be variously configured according totypes of wireless devices. For example, the additional components 140may include at least one of a power unit/battery, input/output (I/O)unit, a driving unit, and a computing unit. The wireless device may beimplemented in the form of, without being limited to, the robot (100 aof FIG. 16), the vehicles (100 b-1 and 100 b-2 of FIG. 16 ), the XRdevice (100 c of FIG. 16 ), the hand-held device (100 d of FIG. 16 ),the home appliance (100 e of FIG. 16 ), the IoT device (100 f of FIG. 16), a digital broadcast terminal, a hologram device, a public safetydevice, an MTC device, a medicine device, a fintech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 16 ), the BSs (200 of FIG. 16 ), a networknode, etc. The wireless device may be used in a mobile or fixed placeaccording to a use-example/service.

In FIG. 19 , the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor, an Electronic Control Unit (ECU), agraphical processing unit, and a memory control processor. As anotherexample, the memory 130 may be configured by a Random Access Memory(RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory,a volatile memory, a non-volatile memory, and/or a combination thereof.

Hereinafter, an example of implementing FIG. 19 will be described indetail with reference to the drawings.

FIG. 20 shows a hand-held device, based on an embodiment of the presentdisclosure. The hand-held device may include a smartphone, a smartpad, awearable device (e.g., a smartwatch or a smartglasses), or a portablecomputer (e.g., a notebook). The hand-held device may be referred to asa mobile station (MS), a user terminal (UT), a Mobile Subscriber Station(MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or aWireless Terminal (WT).

Referring to FIG. 20 , a hand-held device 100 may include an antennaunit 108, a communication unit 110, a control unit 120, a memory unit130, a power supply unit 140 a, an interface unit 140 b, and an I/O unit140 c. The antenna unit 108 may be configured as a part of thecommunication unit 110. Blocks 110 to 130/140 a to 140 c correspond tothe blocks 110 to 130/140 of FIG. 19 , respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from other wireless devices or BSs. Thecontrol unit 120 may perform various operations by controllingconstituent elements of the hand-held device 100. The control unit 120may include an Application Processor (AP). The memory unit 130 may storedata/parameters/programs/code/commands needed to drive the hand-helddevice 100. The memory unit 130 may store input/output data/information.The power supply unit 140 a may supply power to the hand-held device 100and include a wired/wireless charging circuit, a battery, etc. Theinterface unit 140 b may support connection of the hand-held device 100to other external devices. The interface unit 140 b may include variousports (e.g., an audio I/O port and a video I/O port) for connection withexternal devices. The I/O unit 140 c may input or output videoinformation/signals, audio information/signals, data, and/or informationinput by a user. The I/O unit 140 c may include a camera, a microphone,a user input unit, a display unit 140 d, a speaker, and/or a hapticmodule.

As an example, in the case of data communication, the I/O unit 140 c mayacquire information/signals (e.g., touch, text, voice, images, or video)input by a user and the acquired information/signals may be stored inthe memory unit 130. The communication unit 110 may convert theinformation/signals stored in the memory into radio signals and transmitthe converted radio signals to other wireless devices directly or to aBS. The communication unit 110 may receive radio signals from otherwireless devices or the BS and then restore the received radio signalsinto original information/signals. The restored information/signals maybe stored in the memory unit 130 and may be output as various types(e.g., text, voice, images, video, or haptic) through the I/O unit 140c.

FIG. 21 shows a vehicle or an autonomous vehicle, based on an embodimentof the present disclosure. The vehicle or autonomous vehicle may beimplemented by a mobile robot, a car, a train, a manned/unmanned AerialVehicle (AV), a ship, etc.

Referring to FIG. 21 , a vehicle or autonomous vehicle 100 may includean antenna unit 108, a communication unit 110, a control unit 120, adriving unit 140 a, a power supply unit 140 b, a sensor unit 140 c, andan autonomous driving unit 140 d. The antenna unit 108 may be configuredas a part of the communication unit 110. The blocks 110/130/140 a to 140d correspond to the blocks 110/130/140 of FIG. 19 , respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous vehicle 100. The control unit 120 may includean Electronic Control Unit (ECU). The driving unit 140 a may cause thevehicle or the autonomous vehicle 100 to drive on a road. The drivingunit 140 a may include an engine, a motor, a powertrain, a wheel, abrake, a steering device, etc. The power supply unit 140 b may supplypower to the vehicle or the autonomous vehicle 100 and include awired/wireless charging circuit, a battery, etc. The sensor unit 140 cmay acquire a vehicle state, ambient environment information, userinformation, etc. The sensor unit 140 c may include an InertialMeasurement Unit (IMU) sensor, a collision sensor, a wheel sensor, aspeed sensor, a slope sensor, a weight sensor, a heading sensor, aposition module, a vehicle forward/backward sensor, a battery sensor, afuel sensor, a tire sensor, a steering sensor, a temperature sensor, ahumidity sensor, an ultrasonic sensor, an illumination sensor, a pedalposition sensor, etc. The autonomous driving unit 140 d may implementtechnology for maintaining a lane on which a vehicle is driving,technology for automatically adjusting speed, such as adaptive cruisecontrol, technology for autonomously driving along a determined path,technology for driving by automatically setting a path if a destinationis set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, etc. from an external server. The autonomous drivingunit 140 d may generate an autonomous driving path and a driving planfrom the obtained data. The control unit 120 may control the drivingunit 140 a such that the vehicle or the autonomous vehicle 100 may movealong the autonomous driving path according to the driving plan (e.g.,speed/direction control). In the middle of autonomous driving, thecommunication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. In themiddle of autonomous driving, the sensor unit 140 c may obtain a vehiclestate and/or surrounding environment information. The autonomous drivingunit 140 d may update the autonomous driving path and the driving planbased on the newly obtained data/information. The communication unit 110may transfer information about a vehicle position, the autonomousdriving path, and/or the driving plan to the external server. Theexternal server may predict traffic information data using AItechnology, etc., based on the information collected from vehicles orautonomous vehicles and provide the predicted traffic information datato the vehicles or the autonomous vehicles.

Claims in the present description can be combined in a various way. Forinstance, technical features in method claims of the present descriptioncan be combined to be implemented or performed in an apparatus, andtechnical features in apparatus claims can be combined to be implementedor performed in a method. Further, technical features in method claim(s)and apparatus claim(s) can be combined to be implemented or performed inan apparatus. Further, technical features in method claim(s) andapparatus claim(s) can be combined to be implemented or performed in amethod.

1. A method for performing wireless communication by a first device, themethod comprising: transmitting, to a second device, first sidelinkcontrol information (SCI) related to initial transmission through afirst physical sidelink control channel (PSCCH), wherein the first SCIrelated to the initial transmission includes scheduling information ofsecond SCI related to the initial transmission transmitted through afirst physical sidelink shared channel (PSSCH) related to the firstPSCCH; transmitting, to the second device, the second SCI related to theinitial transmission and a medium access control (MAC) protocol dataunit (PDU) through the first PSSCH, wherein the second SCI related tothe initial transmission includes location information related to theinitial transmission of the first device; transmitting, to the seconddevice, first SCI related to retransmission through a second PSCCH,wherein the first SCI related to the retransmission includes schedulinginformation of second SCI related to the retransmission transmittedthrough a second PSSCH related to the second PSCCH; and transmitting, tothe second device, the second SCI related to the retransmission and theMAC PDU through the second PSSCH, wherein the second SCI related to theretransmission includes the location information related to the initialtransmission of the first device.
 2. The method of claim 1, wherein,based on that the first device receives hybrid automatic repeat request(HARD) negative acknowledgment (NACK) from the second device, the MACPDU is retransmitted.
 3. The method of claim 1, wherein a method of HARQNACK-only feedback is enabled.
 4. The method of claim 3, wherein themethod of HARQ NACK-only feedback is based on a distance between thefirst device and the second device.
 5. The method of claim 4, whereinthe distance between the first device and the second device iscalculated based on the location information related to the initialtransmission of the first device.
 6. The method of claim 1, wherein,based on that location information of the second device is changed, thesecond SCI related to the retransmission includes the locationinformation related to the initial transmission of the first device. 7.The method of claim 1, wherein, based on that location information ofthe second device is changed, at least one of a location related to theinitial transmission of the second device or a location related to theretransmission of the second device is used to calculate a distancebetween the first device and the second device.
 8. The method of claim1, wherein, based on that location information of the first device isunavailable, an HARQ feedback method not based on a distance between thefirst device and the second device is configured.
 9. The method of claim8, wherein the HARQ feedback method is a method of NACK-only feedback.10. The method of claim 8, wherein the HARQ feedback method is a methodof acknowledgment (ACK) or NACK feedback.
 11. The method of claim 10, atleast one of information regarding a group size is received, and whereina number of PSFCH candidate resources in a resource pool related to HARQfeedback is greater than or equal to the group size.
 12. The method ofclaim 1, wherein the MAC PDU is blindly retransmitted.
 13. The method ofclaim 1, wherein, based on that a time duplex division (TDD)uplink-downlink (UL-DL) configuration is not configured,TDD-configuration information in a physical sidelink broadcast channel(PSBCH) based on a pre-configured rule is determined.
 14. A first deviceadapted to perform wireless communication, the first device comprising:one or more memories storing instructions; one or more transceivers; andone or more processors connected to the one or more memories and the oneor more transceivers, wherein the one or more processors execute theinstructions to: transmit, to a second device, first sidelink controlinformation (SCI) related to initial transmission through a firstphysical sidelink control channel (PSCCH), wherein the first SCI relatedto the initial transmission includes scheduling information of secondSCI related to the initial transmission transmitted through a firstphysical sidelink shared channel (PSSCH) related to the first PSCCH;transmit, to the second device, the second SCI related to the initialtransmission and a medium access control (MAC) protocol data unit (PDU)through the first PSSCH, wherein the second SCI related to the initialtransmission includes location information related to the initialtransmission of the first device; transmit, to the second device, firstSCI related to retransmission through a second PSCCH, wherein the firstSCI related to the retransmission includes scheduling information ofsecond SCI related to the retransmission transmitted through a secondPSSCH related to the second PSCCH; and transmit, to the second device,the second SCI related to the retransmission and the MAC PDU through thesecond PSSCH, wherein the second SCI related to the retransmissionincludes the location information related to the initial transmission ofthe first device.
 15. (canceled)
 16. (canceled)
 17. (canceled) 18.(canceled)
 19. (canceled)
 20. (canceled)
 21. The first device of claim14, wherein, based on that the first device receives hybrid automaticrepeat request (HARQ) negative acknowledgment (NACK) from the seconddevice, the MAC PDU is retransmitted.
 22. The first device of claim 14,wherein a method of HARQ NACK-only feedback is enabled.
 23. The firstdevice of claim 22, wherein the method of HARQ NACK-only feedback isbased on a distance between the first device and the second device. 24.The first device of claim 23, wherein the distance between the firstdevice and the second device is calculated based on the locationinformation related to the initial transmission of the first device. 25.The first device of claim 14, wherein, based on that locationinformation of the second device is changed, the second SCI related tothe retransmission includes the location information related to theinitial transmission of the first device.
 26. A processing deviceadapted to control a first device, the processing device comprising: oneor more processors; and one or more memories operably connected to theone or more processors and storing instructions, wherein the one or moreprocessors execute the instructions to: transmit, to a second device,first sidelink control information (SCI) related to initial transmissionthrough a first physical sidelink control channel (PSCCH), wherein thefirst SCI related to the initial transmission includes schedulinginformation of second SCI related to the initial transmissiontransmitted through a first physical sidelink shared channel (PSSCH)related to the first PSCCH; transmit, to the second device, the secondSCI related to the initial transmission and a medium access control(MAC) protocol data unit (PDU) through the first PSSCH, wherein thesecond SCI related to the initial transmission includes locationinformation related to the initial transmission of the first device;transmit, to the second device, first SCI related to retransmissionthrough a second PSCCH, wherein the first SCI related to theretransmission includes scheduling information of second SCI related tothe retransmission transmitted through a second PSSCH related to thesecond PSCCH; and transmit, to the second device, the second SCI relatedto the retransmission and the MAC PDU through the second PSSCH, whereinthe second SCI related to the retransmission includes the locationinformation related to the initial transmission of the first device.